To Homeschool on Mars

www.ifitbreaks.com

If you read in your web browser, it should remember your place even if you close the browser and return later. If you know how to sideload files or your phone is good with epub, you can download the file epub or Kindle format .

One

"Well, the docking bay is finally pressurized," the captain's drawl came over the intercom. "The Booker Family will please disembark immediately so you don't get run over by a bot once we start unloading the containers. If anybody is too sick to move, ask a crewman and we'll rig a stretcher. And welcome to Mars."

"I don't feel right," ten-year-old Liza said as soon as she wriggled out of the safety harness. "My stomach is funny."

"Use your bag if you have to throw up," her mother urged, fumbling in her purse for her spare.

"It's not that funny, just weird."

"Because gravity on Mars is a third of Earth's," Henry said. The freshly minted teenager had celebrated his thirteenth birthday during the voyage from Earth, and he had memorized every fact he could find about the red planet. "The container ship was spinning during the trip out, and we weighed almost two-thirds as much in our cabin on the outer deck as we did back home. Here you only weigh around twenty-three pounds."

"Don't jump, Liza," Eli Booker warned his daughter, but it was already too late, and she crashed into the ceiling with her arms outstretched to take the impact.

"That was great," the ten-year-old said as she dropped back to the deck at what seemed to be an impossibly slow rate. "I'm going to be a champion gymnast."

"Except every other girl on Mars has the same advantage," her mother said with a sigh. "Please don't do that anywhere with a high ceiling until we adjust to lower gravity. Your mass hasn't changed, and you could hurt yourself landing."

"Get your backpacks, kids," Eli said and pulled one of the wheeled duffels out from the storage compartment. He was above average height for a man, with broad shoulders and muscled arms that came from working with heavy equipment rather than from a pill bottle. "I could manage both of these if you're tired, Faya. Together they weigh less than just one did back on Earth."

"I'm fine," Faya said. She did a quick inspection of the cabin and collected some of the children's toys that had escaped notice while they were preparing for landing, including a pair of mixed-reality Shades with wide pink frames. A small woman, almost a head shorter than her husband, her movements were quick and certain. "You heard the captain. We should get moving before they tell us that we're stuck in place until all the containers are unloaded."

"Can I open the ceiling door?" Henry asked. "I've been waiting for weeks, and the curiosity is killing me."

"It's not the ceiling now that we've landed, but go ahead," his father said. "It's a smart design for a ship that can land on Mars and the moons of the gas giants. I wouldn't have noticed that the walls and floors were interchangeable if the furniture mounted on rails hadn't given it away."

The door opened on the same corridor running around the cylindrical ship's circumference where they had walked for exercise, but what had been a wall was now the floor. Henry took a moment to get oriented and then pointed. "The closest elevator is that way."

"Everybody follow Henry," his mother said. "Hopefully we all fit in the elevator with the luggage."

It was a tight squeeze, and Liza looked extremely queasy during the elevator's descent during which their weight dropped to nothing. She kept running her hand through her glossy black hair, and her sibling moved as far away as the space allowed, having already experienced the results of Liza getting sick in Zero-G on the shuttle that took them from their home up to Earth's orbit to board the interplanetary cargo carrier. Several seconds passed before the elevator car began to decelerate, and then there was a jarring bump and the door opened with a whoosh.

"Where are we?" Henry asked before his eyes could adjust from the brightly lit elevator to the dim docking bay lights.

Eli stepped out of the car, pulling one of the over-sized duffle bags with him, and looked up. "We're under the ship," he announced. "The elevator shaft extends just like landing gear. But it looks like our side of the ship, if cylinders have sides, is turned away from the passenger terminal. We'll have to do some walking."

"Underneath the ship?" Faya asked doubtfully. "I know that the shortest distance between two points is a straight line, but still…"

"I was going to suggest going around the outside myself. The lighting under here isn't very good."

"Third Officer Larkin, the one who showed me the bridge, said we were their first passengers in a decade," Henry said as the family group made their way past the massive landing gear into the cavernous space of the docking bay. "Not because they don't have space, but because nobody wants to leave Earth."

"The air seems a bit thin to me," Faya said. "I'm running out of breath just walking."

Eli squinted up at the distant ceiling. "This whole docking bay was open to the Martian atmosphere when we landed, and it must have taken some time for those bay doors to close before they could start repressurizing. That's engineering on a massive scale."

"Why aren't there any people?" Liza asked. The ten-year-old was carrying a small backpack that contained a few of her favorite possessions, and with each bouncing step, she appeared ready to launch herself into the air. "I know we were the only passengers on our ship, but we can't be the only people on Mars."

"There used to be passenger liners from Earth to Mars every twenty-six months, one going each direction," Henry answered immediately. "But that ended centuries before we were born."

"And there's our goal," Eli said, pointing his family toward a large sign in a well-lit area. "MarsCo Customs and Immigration," he read out loud. "It's going to be a change living on a world that's run by a business."

"It's why we're here," his wife said. Her conscience pricked her that they hadn't been entirely forthcoming with their children about why they were leaving Earth, and she hid a grimace. "Strange. I don't see anybody at the counter."

"I hope we don't have to wait until tomorrow to get in. My wristcomm has already synched to local time from MarsNet, and it's just past 15:00, or three in the afternoon. Maybe they worked an early shift, and everybody has gone home for the day."

"There was a woman sitting behind that other counter who just ducked down," Henry said. "I'm sure I saw a head move."

"I saw her too," Liza piped up. "She has hair like a princess."

"Let's just check the official immigration counter first," Eli said. "Maybe they left instructions for filling out forms with our wristcomms. We don't know how things work on Mars."

Just before the family reached the customs and immigration counter, a young woman's voice called, "There's nobody there."

"They've gone home for the day?" Faya asked, turning to see the girl with the elaborate hairstyle who had stood up behind the counter at the other booth.

"MarsCo hasn't sent anybody to work at the immigration counter since one of the habitats in the asteroid belt disincorporated and half the population came here," the teen replied cheerfully. "Are you guys lost?"

"We know exactly where we are," Eli replied over his shoulder as he continued to the official counter to see if there was any indication of what immigrants were expected to do. "We just don't know where we're going."

"A hotel, I guess," Faya told the teen as she approached the kiosk, towing the other large duffel behind her. "We'll need to find temporary housing soon, but it's probably too late to do anything today."

"You're about a hundred years late for a hotel," the girl told her. "Fortunately for you…" she pointed at the front of her kiosk and frowned at the lack of response. "Can't any of you read my printing?"

"I can read fine, but there's nothing there," Henry told her.

"But I - oops. I forgot to put the sign out." The slender teenager produced a thin sheet of metal with tape on the edges to prevent cuts, and leaning over the counter, began to lower it into place. Then she realized the print was facing the wrong direction, and with a frustrated sigh, flipped the sign around and held it up for the family to read.

"Maps and guided tours, rentals, E-rations," Faya read. "What are E-rations?"

"You know, packaged meals for explorers that last for decades," the girl said, and then hastily amended herself. "All of these were manufactured within the last month, though. I have a cousin at the factory, and she gets me the quality control rejects at a discount."

"I don't think we're desperate enough to buy rejected food yet," Eli told the girl as the rest of the family gathered in front of the kiosk. "Are you actually trying to help us, or is this a little joke you've worked up to capture video for your friends to watch on MarsNet?"

"Do people do stuff like that on Earth? It sounds like a gross place. I'm here because my uncle, well, my second cousin's uncle, messaged ahead from his container ship and said that a family took passage. I mean, it's not his ship, but he's part of the crew."

"I'm Eli Booker, this is my wife, Faya, and our son, Henry, and the shy one is Liza," Eli introduced the family.

"I'm not shy, and your hair is beautiful," Liza told the girl. "I wish I had braids like that."

"I'm Zest - Zest Twenty-Six if you want the whole thing. And you'll have to grow your hair out for five years if you want braids like mine," Zest continued as she lowered the sign. "It's down to my butt if I don't pile it up like this."

"Twenty-Six," Eli repeated. "Is it a Martian tradition to use numbers for family names?"

Zest looked puzzled for a moment as if his question was so odd that she needed to figure out what he was asking. "My mom is Zest Twenty-Five, her mom is Zest Twenty-Four - the name goes back a way. Most people don't get past Ten."

"Are you really a guide and a rental agent?"

"And is any of that food here?" Henry added. "I'm hungry."

"Yes, yes, and yes," Zest told them. She bent down to retrieve a stack of small boxes which she placed on the kiosk's counter. "E-rations, and the only thing wrong with them is that the boxes are misprinted. They're all chicken and rice with green beans, whatever it says on the label."

Faya produced an energy bar from her purse and gave it to Henry. "I'm vegetarian," she told the girl. "But maybe we could take a few if they aren't too expensive. I'll find something else for myself."

"If you're bothered by killing chickens, the meat is vat-grown from cells. The original chicken probably died from old age back on Earth a thousand years ago."

"Practically all the meat on Earth is vat-grown as well," Faya said. "I just don't like the idea of it."

"Are you worried that there's something wrong with the rations other than the packaging?" Zest asked. "I skipped lunch today so I can eat a little of one in front of you. I'll turn my back and you can pick which."

"That won't be necessary," Eli said. He stood the wheeled duffle on end and glanced over at the immigration counter again. "We're just a bit confused by, well - I was expecting immigration forms, customs, agencies renting ground transport."

"I can tell you where to borrow an outside SixBy, but I can't imagine you want to go up on the surface right away. The maglev dulls to the burrows are all on-demand. They belong to MarsCo, and they come when you call them."

"But where will we go right now?" Faya asked. It wasn't clear whether she was directing her words to her husband or to Zest.

"That's the rental part of my sign," the teen said proudly. "I've got the perfect place for a family of four. I changed the sheets and everything. It's only a few minutes from here, and it's close to the main tunnel so you can get anywhere on Mars with just a few transfers."

"And how much would an apartment like that cost us?" Eli asked, keeping his tone light to indicate that he was still willing to take the whole thing as a joke in case that's what it was.

"You just pay the standard home expenses if you take it."

"It doesn't have an official price?"

"I don't know what you mean by that," Zest said. "The main reason people live around here is because of the container cargo terminal, which is also why there's such good tunnel access. The last person to live in the apartment was one of my cousins, maybe she's once removed, and she took her family to work in the South a couple of years ago. I already messaged her, and she agreed to let you use all the stuff she left behind rather than having it moved to storage."

"I guess we should see it, but we couldn't sign a long-term lease," Eli said.

"Is that like a contract? We don't do them unless it's something serious. You try the digs for a couple of days, and if they suit, you start paying expenses. If not, you'll be on your way, and I'll wash the sheets again."

"That sounds more than fair, especially since it's getting late and we don't have anywhere else to go," Faya said. "Does it have a kitchen where we can heat those meals?"

"Of course," Zest said. "And I can take you by Gramp's storeroom on the way and you can stock up on food if you don't mind simple stuff. Gramp sells rice, beans, cans, anything that lasts a while. For fresh veg and fruit, you'll have to join a farm club."

"Will there be any trouble with exchanging currency?" Eli asked. "I imagined there would be a bank here where I could deposit R-bucks or access my line of credit, but it looks like that will have to wait until we visit somewhere with a large population."

Zest looked puzzled again, and then she held up her forearm, displaying the round bump where her token was implanted below the skin. "You aren't chipped?"

"Yes, of course we are. But I don't know if they'll work here without being added to the system at a bank or government office."

"Try it. Let's start with the E-rations, they're five each."

"R-bucks?"

"They're five minutes each, not R-thingies. Everything here is priced in MarsCo time-units, but there's probably an exchange rate. I know it works for visitors from the asteroid belt or the gas-giant moons, but I've never met anybody from Earth."

"You speak English," Liza said, proving that she hadn't fallen asleep, despite the fact she had sat down on the floor and was leaning against her mother's legs.

"I speak Martian, but if you want to call it English, suit yourselves," Zest said. She tapped the comm on her wrist and said, "Fifteen-minute transaction charge." Then she held her arm out and looked at Eli expectantly.

He tapped his own wristcomm and said, "Foreign currency purchase. Uh, fifteen minutes." Then he stretched out his arm so that his subcutaneous token came near Zest's, and both of their wristcomms beeped in confirmation. Eli looked at his wrist again for the exchange rate. "Thirty-two replacement dollars, so a MarsCo minute is worth a bit more than two R-bucks."

"You're as tall as my daddy," Liza said to the teenager in an accusatory tone after getting back to her feet. "How old are you?"

"Sorry," Faya said. "We raised them to ask questions, but sometimes their manners - "

"Doesn't bother me," Zest interrupted. "I'm nine, which is why I'm still doing odd jobs rather than apprenticing or going to the U, and I'm probably average height for women on Mars. It's the low gravity."

"You're not nine," Liza objected. "I'm ten!"

"Earth years are about half as long as our years. If anybody asks, tell them you're five."

"Six-hundred and eighty-seven Earth days in a Mars year," Henry confirmed. "You're almost eighteen."

"I'm nine," Zest repeated forcefully. "It's all of you who are going to have to figure out how old you are." She gathered up the boxed meals that Eli had paid for, double-checked the kiosk to make sure she wasn't forgetting anything, and added, "Follow me."

"Where are we going?" Faya asked.

"To the blue tunnel. The dulls in the main tunnel are all sized for cargo containers, and they cost twice as much as a passenger dull."

"That's the third time you've mentioned dulls but we don't know what they are."

Zest stopped and looked over her shoulder at Faya. "Don't you have tunnels on Earth?"

"Under mountains or in the linear cities," Eli said. "We understand that you're talking about some sort of transportation, but we've never heard of dulls."

"I guess it's not their technical name, but that's what everybody calls them. I say it's because they're all made from aluminum that's dull rather than shiny. My oldest brother, who's a real tech-head, says the name has nothing to do with the aluminum, and it's because the tunnels all had to be bored through the rock. But he's always making stuff up."

"I don't get the connection."

"Bored, boring, dull," Zest recited as if she were conjugating a verb according to her own system. "It sounds like a stretch to me."

"Are they still constructing new tunnels?" Eli asked as the girl hit a glowing green button on the wall to open a set of doors.

"Not around here," Zest said. "Everybody in quick, because the airlock doors close automatically after thirty seconds, and an alarm goes off if anything is obstructing them."

"Do you have to pay a fine if that happens?"

"Pay who a what?"

"A penalty, to whatever authority operates the airlock."

"There's no penalty, it's just a really loud alarm that hurts my ears, and I don't know what you mean by an authority," Zest said. The doors through which they'd entered slid shut, and a couple of seconds later, a pair of doors on the opposite side of the airlock opened. "Everybody out."

"But nothing happened!" Henry said, sounding disappointed.

"The airlock is only here to prevent the air in the tunnel from emptying into the docking bay when the bay doors are open for a ship to land." Zest waited for a moment to make sure the whole family had followed and then led them a few steps to the opening of another tunnel with walls so smooth that it could have been a pipe. "Around the big caverns, the dulls all run on automatic and stop at every side passage, which is a real drag. We don't have much passenger traffic around our burrow, so they operate on demand. Do one of you want to try calling it?"

"Like, shouting?" Liza asked.

Zest laughed. "That's a good one. With your comm. Just ask for a dull and it will tell you the waiting time."

"And the price?" Eli asked.

"It won't know that until you get where you're going. The cost is a combination of the energy charge, which is almost nothing, the wear-and-tear on the dull, which never comes to more than a few seconds, plus a maintenance fee that gets billed at the end of the cycle."

"We won't know how much the ride costs until the end of the month?" Eli frowned. "I'm sorry if I keep sounding suspicious, but that's not the way things work on Earth."

"A cycle is a hundred days," Zest told him. "MarsCo does it that way to average out the costs. You can always check the maintenance fee for the last cycle for an estimate of what a trip will cost because it never changes by much."

"Doesn't anything on Mars have a regular price?" Faya asked.

The teenager tapped her comm, said, "Send me a dull for Dov's," and nodded in satisfaction at the numbers that appeared on the small screen. "Forty seconds, and I don't know what you mean by a regular price. We pay what things are worth, and not a second more or less."

"And the - dull," Eli hesitated over the unfamiliar term, "will cost us around forty seconds?"

"That's when it will get here. It will cost about three seconds to Gramp's storeroom, and the maintenance fee might come to ten seconds since there are five of us."

"It's hard to see where MarsCo is earning its profits at that sort of pricing."

"You can worry about that later," Faya told her husband. "I'd rather hear about the local schools. We brought our children's transcripts from Earth, but I'm beginning to suspect that the curriculum here will be so different that the school will be comparing apples and oranges."

"What are local schools?" Zest asked, glancing at her wrist for the remaining time.

"Where we go to learn with Alpha every day," Liza said before her mother could answer. "I'm in fifth grade."

"You still do schools and grades on Earth? I've seen them in imported vids, but I thought it was all made up. Nobody on Mars goes out to school until they get to U, and even then, it's mainly weekends for the social life."

"Do you mean that everyone on Mars homeschools?" Faya asked. "It's not allowed on Earth. Alpha sets the curriculum for all the schools in North America, even in our - "

"Here it comes," Eli interrupted, flashing his wife a significant look. She blushed when she realized what she'd almost said.

A dull metal capsule with no visible means of propulsion floated to a stop right where they were waiting, and a door slid open. "All aboard," Zest said. "It's rude to take any more time than necessary. These local tunnels are only one lane, which means you could be making somebody else wait."

"What if we wanted to go the opposite direction?" Henry asked as they entered the dull, which felt almost like stepping into a small boat floating on water. "If a lot of people are using the tunnel, it could take forever to get anywhere."

"The local tunnels are all loops, so there is no opposite direction. And in answer to your question," she continued, turning to Faya, who had just brought up the rear with the second rolling duffle, "all of the kids take the MarsCo courses at home, if that's what you mean by homeschooling. Even the Oldtimers, and they don't do anything normal."

"Don't you have to tell it where we're going?" Eli asked.

"The dull? I did that when I ordered it. That way the system can plan ahead if there is traffic." Zest plopped down on the padded bench that ran around the outside of the car. "Sit down, everybody. It takes twice as long to get anywhere if somebody is standing because the dull automatically cuts its acceleration for safety."

"Is it magnetic suspension and propulsion?" Henry asked. "I tried to read everything I could about Mars, but there wasn't much from after the original colonization push."

"That was over five hundred years ago! You guys came all the way here without knowing anything about Mars or how we live?"

Eli waited to see if his son would reply, before saying, "We know that the planet is run by MarsCo rather than a superintelligence."

"A superintelligence as opposed to an idiot?" Zest asked.

"Super artificial general intelligence."

"I was kidding, and we don't have artificial general intelligence on Mars. Just the regular kind, and not much of that."

"Whenever I asked Alpha about life on Mars, he told me it's a cold place where people lived in caves and that I wouldn't like it," Henry said. "Alpha says that colonizing space is squandering resources that could be invested on Earth."

"I knew that last part because we had a history lesson about Alpha abandoning the Ark program," Zest said. "And there used to be a lot more people on Mars, but Alpha convinced the lazy ones to move back to Earth by promising them free everything and early retirement. Good riddance to anybody who took the offer."

"It wasn't easy for the people who returned, especially the ones whose families had lived on Mars or the other colonies for generations," Faya said. "They had to go through months of conditioning in orbit to prepare for Earth's gravity before they could be brought to the surface. We heard that some couldn't make the adjustment and were resettled on the moon."

"Serves them right for quitting," Zest said as the dull came to a stop. "We're here. Grab your bags and let's go meet Gramps."

Two

The old men sitting at the chessboard in front of a large shipping container looked up when the family approached. The player on the left, who appeared to be around eighty and hadn't shaved in days, inquired, "Customers or tourists?"

"Both," Zest answered. "Regular cut, Gramps?"

"Five percent," the grizzled man confirmed and rose easily from his chair. "I'm Dov," he introduced himself to the Bookers. "What can I get you?"

"We just arrived on Mars, and the young lady has fixed us up with rations for dinner, but my wife is a vegetarian," Eli explained. "We heard you have rice, beans, maybe some cans. Anything to tide us over until we can get to a real market."

"And what would you call my shop here?" Dov demanded. "A retirement hobby?"

"I didn't mean any offense. It's clear you have a lot of inventory, though how you find anything in there is beyond me."

"Well, you would have been right the first time because it is my retirement hobby. And I find things by turning on the lights and looking for them." He raised his forearm and said, "Lights on," to his wristcomm, and the dim container space was suddenly lit so brightly that it almost hurt the eyes. "I wish I hadn't done that," Dov said, surveying the wall of boxes. "There's supposed to be an aisle down the middle, but I haven't found anybody to restack the boxes since the last shipment came in. Do your children want a little work?"

"I do," Henry said immediately. "I like stacking boxes."

"I'm not sure…" Faya began, but her husband put his free hand on her arm and gave her a little nod. "I mean, I guess we could all help."

"Moving boxes is strictly a job for the young," Dov said. "I used to hire this one to do it," he indicated Zest by jutting his chin in her direction, "but she's aged out."

"I'm young too," Liza piped up.

"Those boxes are probably too heavy for you," Eli told her. "Maybe Zest will show us a little more of the burrow while Henry works."

"With those Earth muscles and our gravity, there's not a box in the container the girl couldn't lift without straining," Dov told him. "I'm the one paying, so I should know."

"Paying?" Henry asked. "For real?"

"You have tokens, don't you?"

Both children turned their forearms so the circular bumps, like a coin that had been slipped under the skin, were visible. "Dad's worked, so I guess ours will too."

"Of course, they'll work," Dov said. "MarsCo licensed the technology from Earth when the colony was established, but we stopped paying royalties when the patents expired."

"The children only have tokens because Alpha requires them for identification when they start school," Eli said. "They're too young to have worked on Earth."

Both old men snorted at this comment, and then Dov held out his own arm and motioned Henry to approach. "There," he said when his wristcomm beeped. "You're on the clock. Come on, young lady. Clock in, or you'll be working for free."

Despite her initial enthusiasm for moving boxes, Liza hung back for a moment, but Henry grabbed her other arm and dragged her over to the old man. There was another beep, and Liza was clocked in.

"Your first job is to bring enough of those boxes out here so the aisle is open again and I can see what's where," Dov said. "Then I'll have to supervise. Can you read Martian?"

"They call it English," Zest told him.

"They can call it whatever they want as long as they can figure out what's in the boxes."

"I read on the ninth-grade level even though I'm in fifth," Liza told him proudly.

"Then let's get moving," Gramps said and clapped his hands sharply. The children set to work, and he asked the parents, "Do either of you play chess?"

"I used to be in a club," Eli said.

"Then see if you can save my position."

Eli shot his wife a bemused look before settling into Dov's seat and surveying the board. The position turned out to be more complicated than he would have expected, and soon he was sunk in thought.

"Well, at least they should sleep well tonight," Faya said to Zest as they watched the kids carrying boxes out of the container and carefully stacking them in the wide tunnel that functioned as a public space. "The container ship corridor lights were on all the time, and I'm afraid we all got a little confused about the difference between day and night."

"The tunnel lights here are cycled to track day and night on the surface," Zest told her, taking a seat on a couple boxes of canned corn that the children had just deposited. "Some families with places close enough to the surface put in sun tubes, but for direct light, you either have to go outside and visit a pressurized greenhouse or move to one of the old agricultural canyons."

"Are there canyons on Mars? I didn't know there was any surface water to create them."

"Billions of years ago it was different, and some of the canyons are really cracks between tectonic plates. Stay here long enough and you'll learn the difference between marsquakes and iceteroids piling in."

"Do you mean asteroids?" Faya asked.

Zest pulled in her legs as Henry passed by carrying two boxes, the upper one of which blocked the boy's forward line of sight. "Why would MarsCo crash asteroids into the planet? Iceteroids are almost all water, the same sort of stuff as comets. Ice wranglers drop them in the atmosphere, where they mainly vaporize or blow up from steam pressure, but sometimes they have a little rocky core that hits with a bang."

"It seems like a risky way to bring in water."

"Cheap, and it keeps the fleet of ice wranglers working. And they do all of the math ahead of time, so they know exactly how big a bang each iceteroid is going to make. Five hundred years of practice is a long time."

"Sar-dines," Liza pronounced, setting a box down near her mother. "What are sardines?"

"Little fish with a strong taste," Faya told her. "Your father doesn't like sardines, so we never had them at home. Is most of your food from Earth, Zest?"

"Those are imported luxuries," the teen told her. "Mars is entirely self-sufficient for everything that matters, and we even export our excess to the asteroid belt habitats and gas giant moons. But people like the occasional can of something from Earth."

"And the rice and beans that you mentioned?"

"That's all grown locally, and the corn is canned two burrows over. The food that Dov imports isn't grown on Mars because there isn't enough demand. And some old people eat anchovies. We farm normal fish, but not the weird stuff."

"It was nice of him to hire the children just to help them settle in."

Zest looked up from checking something on her wristcomm. "He was serious about moving boxes being a job for children. I mean, you might not want to hire kids for fragile stuff, but it's important to give them a chance to earn units on their own so they learn that it's not all about MarsCo."

"From the way that MarsCo ends up in every discussion, it sounds like they do run the planet," Faya said, smiling to show that she wasn't trying to criticize.

"They? MarsCo is us - all of us. Even your children are equity holders now."

"I don't understand. Just for coming here we get shares in the corporation?"

"It's a cooperative, not a corporation, and you don't get anything, you work for it," Zest said in exasperation at Faya's lack of understanding. "The children have already been working for at least five minutes, so that's how many units of MarsCo they own."

"But…" Faya paused for a moment to think. "You're saying that units serve as both currency and shares in MarsCo?"

"They're units, aren't they? How else would you keep track of everything? When we work directly for MarsCo, we get paid in units, and when we work for each other or buy and sell merch, we use the same units for that. It's all recorded on our tokens. Look," she continued, tapping at her wristcomm. "I own four thousand, two hundred and sixty-nine hours of MarsCo, if you round up a few minutes."

"And as you get older, your share rises?"

"Everybody works for MarsCo one day a week unless they hire a substitute, but you won't save any units doing that."

"You've lost me again," Faya said. She looked over to see if her husband was paying attention to the conversation, but he was immersed in the game. "Everybody has to work for MarsCo, even if they have another job?"

"If you're going to live here, you do. Sometimes, if people are really into doing one thing, like, I don't know, a farmer bringing in a crop, they can hire a sub. But the tradition is for the sub to charge whatever the person hiring them makes while postponing the MarsCo day. And then the farmer still has to make the day up later, though he'll get paid straight time, of course."

"How would the substitutes know what the person hiring them earns that day?"

Zest shrugged. "I've never subbed, it's not common around here, but my sibs who went to U in the south all tried it a few times to raise party funds. My sister once subbed for an artist, and she earned over a hundred hours that day because the woman was having an exhibition and she sold a painting. A hundred hours for one day. Can you imagine?"

"It sounds complicated and not fair," Faya said. "What if the artist spent a hundred hours or more creating the painting and it just happened to sell on the day your sister was substituting?"

"Then the artist should have had more sense than to have a show on a day she hired a sub."

"And you said that my children are earning a minute unit for every minute they work. But surely you could move twice as many boxes in the same amount of time, so how much would Dov pay you?"

Zest stared at Faya like the Earth-woman had grown a third eye. "A minute is a minute. Do you think that my time is worth more than your children's time?"

Faya was so taken aback by the teenager's question that she decided to leave the subject until she had learned more about conditions on Mars. She also wasn't sure how long she could count on Zest to hang around and answer her questions, and there were more important things she needed to know.

"Can you tell me more about the education system?" Faya asked. "Between summer vacation and the trip here, our children have never been out of school so long, and I don't want them falling behind."

"Behind who?" Zest asked, her curiosity piqued. "Is education on Earth a competition?"

"No - I mean, yes - I suppose it is, in a sense. How the children do in school affects their opportunities at the next level of education. In our community, we don't look at it as a competition, but all schools on Earth are run by Alpha, so children who want to continue their studies at a higher level don't have any other options."

"My sister made me watch a holo-drama from Earth that was about a school for kids who were studying to be in the entertainment industry. All the girls were mean to each other, and I lost interest in a hurry. Anyway, it's nothing like that here, and there's nobody to fall behind. Everybody does the courses at their own speed, and when they finish, they can go on to the next one if they want."

"There's no particular age to start at university?"

"Why would there be?" Zest asked in return. "One of my brothers started taking courses from U when he was seven, and my mom went back after she had me."

It took Faya a moment to remember that seven in Martian years was closer to fourteen in Earth years, though that still seemed very young to start university. "And how about minimum requirements? What if it takes a slow student - " she did a little mental math, "ten years to finish the basic courses?"

"If it takes them that long, you have to give them credit for not giving up. It's not like anybody is twisting their arms and forcing them to study."

"But surely the government, I mean, MarsCo, requires parents to see that their children are educated," Faya said. "It's not like you're living on some ancient frontier where children's labor is required just to survive."

Zest cocked her head a bit to the side, and for once, she took a little time before responding. "I'm not a parent, so maybe I'm missing something here, but everybody I know is pretty satisfied with the courses. MarsCo doesn't force children to study, that's up to their families. Kids get a token on their fourth birthday, but they aren't allowed to do more than an hour a day of private work. That goes up a half hour every year until they're eight, and then they can work as much as they want."

"So - forgive me if I translate to Earth years for myself out loud - from just under eight Earth years old, children can work one hour a day, and by the time they're sixteen Earth years old, that's up to four hours a day."

"Which should really be higher," Zest said in disgust. "By then I'd finished all my courses, except for chemistry, and when I used up my hours for the day, I spent my time reading or working on business ideas that didn't get very far. My parents kept sending me to workshops, like pottery, cooking, and bicycle repair, but it's not the same as paying work."

"You have bicycles on Mars?" Faya asked. "Where do you ride them?"

"In the tunnels, of course. One of the reasons that you don't have to wait long for a dull around here is that everybody is riding bicycles through the bypass tunnels. They work on the surface too, though you have to keep up with cleaning dust out of the gears, and there's all of the complications with breathing and not freezing."

"Just one more question," Faya said to Zest as the teen stood up. "How do I register the children for these homeschool courses you talked about, or is it all done over the MarsNet?"

"You can do it that way, but it's better to go by the local office to get set up. Today is Wednesday, and I've got something scheduled tomorrow, but if you can wait until Friday morning, I'll come by and bring you."

"You're a lifesaver. I hope you'll let us pay you something for all of your help."

"Something?" Zest laughed as she headed for the container to check on the children's progress. "I've been on the clock since you walked up to my kiosk. When there's nobody at the immigration counter, and there never is, whoever is willing can step in for MarsCo."

Faya followed the teenager, and they met Liza coming out with her arms empty.

"We moved all of the boxes and put some of them where Dov told us," Liza reported proudly. "Now you can go all the way to the back."

"There's certainly more variety than I thought there would be," Faya said, skimming the labels as she entered the shipping container, which was about the same size as the containers carried by ships or electric wheelsets on Earth. "I'm not sure I want to buy in quantity, though. Especially when we're in temporary lodging."

"You don't have to take a whole carton," Dov said, returning from the back of the container where he'd been checking the inventory. "I've got plastic bags that you can fill with whatever weight you want of the grains, beans, and other staples. On the luxury goods from Earth, you can take a single can or package if that's all you want." He held his arm out toward Liza. "Time to clock out, young lady."

The girl approached and waved her arm under the old man's so quickly that there was no confirming beep from his wristcomm, and she had to do it again. "How much did I earn?" she asked eagerly.

"Seventeen minutes and eleven seconds. You're now an official stakeholder in MarsCo."

Liza waved her arm triumphantly in front of her mother. "And I did as much work as Henry, almost."

"And you really would have paid an adult the same, if an adult did the work, I mean?" Faya asked.

"I thought I heard my granddaughter explaining it all to you," Dov said. "You might get a bonus multiplier on some jobs if you've gone over eight hours that day or forty hours that week, but it's up to negotiation between you and the employer. MarsCo always pays straight time."

"But you're not MarsCo. I mean, I understand that you're all owners, but I thought this store was your own."

"I'm not sure I would dignify a container full of whatever I can sell by calling it a store," Dov said with a chuckle as he untied the top of a large sack of rice. He handed Faya a plastic bag and filled a large scoop from the sack. "Say when," he told her, tilting the scoop so the rice ran into the open plastic bag in a steady stream.

"That's fine," Faya said a few seconds later when there was enough for a week's worth of rice at every dinner for the family.

"And I wasn't ignoring your question, I'm just past the age of trying to do two things at the same time," the old man said as he replaced the scoop in the bag and retied the elastic around the top. "MarsCo has no share in this little retail kingdom of mine. I pay straight time because almost every other employer on the planet does the same. If I offered less, nobody would agree to work for me."

"But if there are more people than there are jobs…" she trailed off as she noticed Dov shaking his head.

"MarsCo is always hiring, any hour of the day or night. Maybe when the first phase of the terraforming job is finished and people can go outside without an oxygen supply, things will change, but it won't happen in your lifetime - or for another twenty generations at the minimum." Then he took the bag of rice back from her, placed it on a scale, and read off the display while extending his arm. "That will be eight minutes and fourteen seconds."

Faya brought her forearm near, and her wristcomm repeated the amount and asked for confirmation. "Approved," she said, and both of their comms beeped. "I guess it handled the exchange rate without a problem."

"Can I get you anything else?" Dov asked. "If I know my granddaughter, she'll have staged the apartment for you with some fruit and things in the fridge."

"She sold us E-rations."

"We're an entrepreneurial family, and if she'd told you about the fruit ahead of time, you might not have bought the rations," the old man said. "It looks like your husband has improved my position, so I think I'll take over and let you get moved in."

By the time they reached the apartment, Eli was carrying Liza, who suddenly discovered she'd had enough for the day, even in low gravity. The exaggerated bounce was also gone from Henry's steps. Zest palmed open the door's lock screen and made sure it registered a new impression from each member of the family as they entered. "What do you think?" she asked, after confirming that Faya's palm scan had been accepted.

"I have to admit that the living room looks nicer than I'd hoped, but I'll have to see the rest before I answer," Faya said. "The furniture looks more modern than what we brought from home."

"You brought furniture with you? All the way from Earth? Why?"

"We didn't know what would be available here, and the cost for one shipping container wasn't at all expensive. The clerk told us that freight traffic to Mars has been falling as long as he could remember."

"You saw the pedestrian tunnel we came through," Zest said. "You can't get a container anywhere near here. You'll have to unpack it in the commercial area, near Gramps, and then make as many cart runs as it takes."

"It looks like your cousin left everything behind." Faya opened a few kitchen drawers and ran her hands over the inductive stovetop, which gleamed almost as if it was new. "If she doesn't mind us using her things, there's no reason for us to unpack before we find a permanent place."

"Look in the fridge."

"I hope she cleaned it out before she left because nothing would - did you do all of this for us?" Faya interrupted herself. "It's so nice of you, even if you are on the clock for MarsCo."

"I bought the fruit and veg for the fridge on spec, so you owe me fifty-two minutes if you keep it," Zest said. "It was easy to pull together because a few local families traveled for a big wedding this week and they were willing to unload part of their farm-share allocations. I insisted on paying them twenty minutes each so they wouldn't think you were taking charity, and there's twelve minutes commission in there for me."

"But all of this is so fresh. Couldn't they have left it in the fridge until they returned?"

"That's not how the farm-shares work. You have to sign up for a hundred days, minimum, and your allocation comes every week whether you're here to eat it or not. The families who are signed up do a lot of trading with the few who aren't."

Eli entered the kitchen, still carrying Liza. "You have to see the bedrooms," he said. "There are three of them, and everything is set for going to sleep tonight. There are towels in the bathroom and shampoo in the shower, or at least, I think that's what it is."

"Green," Zest confirmed. "Pretty much everybody uses it, and if it has another name, I've forgotten. Gramps buys it by the barrel, and we just keep refilling the plastic containers." She set the three E-ration boxes she was still carrying under one arm on the counter. "Have you ever used a microwave oven? I read somewhere that there are places on Earth where nobody has electricity."

"Maybe a thousand years ago," Faya said with a laugh. "After Alpha solved all of the issues with fusion, everybody ended up with plenty of power."

"And how about that greenhouse thing?"

"Alpha pulled the excess carbon out of the atmosphere and keeps everything in balance now. Compared to the dawn of the space age, Earth is a paradise."

"Then why did you leave?" Zest asked.

"There's always a serpent," Faya told her.

Three

"Are we going to live in caves from now on?" Henry asked his father as they walked through the bypass tunnel on their way to meet Zest's uncle, who had turned out to be the closest thing to a real estate agent in the local area.

Eli laughed. "Is that what you think of the apartment we're renting?"

"It is underground, and the walls are all rock. Is there another name for it?"

"I think Zest just called it an apartment. And a community of homes is a burrow."

"And a really big burrow is a cavern, cave - r, n," Henry said as if this proved his point.

"We'll ask Zest's uncle if there are any other options, but I imagine that living on the surface would be too expensive," Eli said. "The houses would have to be sealed so the air doesn't leak out, and we'd still need to come and go through tunnels."

"Mars has an atmosphere. It's just not very good."

"What do you mean?" Liza asked her older brother.

"There was always an atmosphere, even before humans got here, but it was really thin and you couldn't breathe it," Henry explained. "It was thicker when the planet was young, but the gravity here isn't strong enough to hold the atmosphere as close as Earth's, so it slowly leaked off into space or got stripped away by solar winds."

"There's wind in space? You told me there isn't any air."

"It's not that kind of wind, it's charged particles shot out by the sun. They just call it solar wind, and Earth's atmosphere is protected by its magnetic field."

"I liked our cabin on Earth," Liza said. "It was cozy, even though the walls were all metal, and all of my friends lived on the same corridor. And if we were back home, I could put on my Shades and ask Alpha to explain about the wind thing."

"If you'd been born a thousand years earlier, we'd have been living in a house made from recycled plastic," Eli told the children. "And in the big linear cities where most of Earth's population lives, the buildings are made from concrete, steel, and glass."

"Aren't some of them empty?" Henry asked.

"Sections are empty, not entire linear cities. They're each built to house tens of millions of people, and I guess Alpha figured it was better to have spare capacity. It's just more efficient to maintain all of the services if people live close together rather than spread out."

"But why?" Liza asked, as her father pulled her to the side to allow a group of bicyclists on their way to work pass without having to string out single file.

"Why is it more efficient to maintain fewer sections of a linear city, or why did Alpha have the construction robots build so many of them?"

"The second one."

"I suspect because the incremental cost was so low," Eli said. "Earth has robot miners excavating iron ore for factories where robots make steel, and robots running concrete plants with plentiful fusion power. Robots build themselves in robot factories, and my job as a robotics engineer was mainly nostalgia on Alpha's part. His robots replaced the need for humans to work many centuries ago."

"Why did Alpha make it so hard for us to leave Earth?" Henry asked.

"I think all of those exit interviews were Alpha's way of trying to figure out if he'd failed us or if we're simply malfunctioning."

"But we aren't robots."

"Humans malfunction more often than robots do, though there's another name for it," Eli said with a grin. "Back when artificial general intelligence first appeared, scientists and politicians alike were worried that it would turn on us. Their attempt to align thinking machines with humans overshot the mark, and the result is Alpha and his addiction to serving humanity."

"But people are always complaining that Alpha didn't let them do something they wanted," Henry said.

"That's what I meant when I said that alignment overshot its goal. Superintelligence is smarter than we are, that's the definition. The way Alpha sees things, he knows what's better for us than we know ourselves. But Alpha lets Mars and the outer colonies go their own way because alignment was about serving the people on Earth."

Henry came to a sudden stop and stared at his father. "How come you're only telling me now? I was the best student in my history class, and I never heard of alignment."

"Your mother and I didn't tell you for your own protection. I know this is going to be difficult to understand, but if we had told you the truth, it would have been too hard for you to keep it inside. Alpha believes that he's perfectly aligned with humanity, so if somebody suggests Alpha isn't acting in our best interests, Alpha is compelled to fix the problem. Alpha knows that he can't be the problem, so that leaves the people."

"What does that mean?" Liza asked.

"That means it's the people who have to change," her father said, and started to walk again. "We didn't want to lose you to special schools, or perhaps Alpha would have concluded that your mother and I are so incompetent that you needed new parents."

"But the people here get to choose for themselves?" Henry asked.

"That's what we're going to find out. We were hoping that the schools on Mars would be different since a super artificial intelligence never controlled this planet."

"Martians don't have schools!" Liza said gleefully, and then her face fell. "But I miss Alpha, and my Shades don't work here."

"We're too far from Earth for mixed reality," Eli said. "Even when the planets are at their closest point, it takes more than four minutes for a radio signal to reach Mars."

"Why didn't you explain all this while we were on the container ship?" Henry asked.

"Because we didn't know for certain whether MarsCo would let us live here. Alpha made it difficult to find any of that sort of information about Mars because he doesn't want people to leave Earth anymore."

"Is that him?" Henry asked, shifting his attention to a tall man waiting at the next cross tunnel. "Zest said her uncle would be wearing a yellow hat."

"Good eyes," Eli said, happy to postpone the rest of the conversation about the dark side of the paradise they'd left behind.

Zest's uncle spotted the family group a second later, and he approached to greet them with a lope that covered the distance in half of the time it would have taken the Earthers.

"I'm Patrick, but everybody calls me Pat," he introduced himself. "Going by the descriptions I was given, you must be Eli, Henry, and Liza." He shook hands with each of them in turn. "I don't mean to rush you, but I have another job in two hours, so today I want to give you a lightning tour of what's available in our burrow. Tonight I'll send you all the details over your comm, and when you're ready, we'll take as much time as you want on the promising candidates."

"You're taller than Zest," Liza said, the words coming out like an accusation. "I've never met anybody as tall as you."

"It's the gravity," Pat explained. He turned and began leading them to the cross tunnel at a pace that made the children jog to keep up. "Neither of you has hit your growth spurts yet, and I bet you both end up taller than your dad. Ask Zest to get you all fitted out with weighted clothes as soon as possible or you'll start losing muscle mass faster than you can gain it back."

"We're moving here," Henry said. "If we never return to Earth, and everything here weighs a third as much, why do we need big muscles?"

"Millions of years of evolution gave us bodies optimized for Earth's gravity, and you'll end up with weak bones and other problems if you don't exercise to keep everything in balance. The sweater I'm wearing is weighted, as are my boots and the leggings, and with all of that, I still only weigh about half of what I would on Earth. But it's enough to keep me from turning into a walking skeleton, like some of the Oldtimers."

"The muscle loss gets worse with age? We met Dov and a friend of his yesterday, and they both looked pretty healthy."

"They're thin enough under their clothes, but when people on Mars talk about Oldtimers, they're referring to people who claim to be directly descended from the original settlers. Oldtimers believe that natural selection has made them the true Martians, and they don't wear weighted clothes or use exercise equipment."

"And they look like skeletons?" Henry asked. "I don't think I want to see that."

"I'm exaggerating a little, but if you think that I'm tall, I'm only average for an Old Timer. They often refer to the rest of us as Thicks because we carry more flesh than they do," Pat said, ushering his charges into another tunnel. "There are several vacant homes just around the next bend."

"How's their health otherwise?" Eli asked. "Do these Oldtimers have problems with broken bones?"

"I suppose it's a mixed bag. A man built like you could break their ribs with a punch, not that anybody tolerates that sort of behavior around here," he amended himself hastily. "But on average, they live longer than the rest of us, maybe because their hearts are doing less work. You'd have to talk with a medic. And here we go." Pat palmed the glowing pad next to the metal doors sealing off the side tunnel, and there was a sudden breeze at their backs.

"It's dark," Henry observed unnecessarily.

"That's odd. There should be - good," he interrupted himself as the overhead tunnel lights came on. "It may have been years since anybody came through this way, and I'll bet there's a sticky relay in the control circuits. I'll post a repair order to MarsCo."

"I'm a robotics engineer by profession so I'm comfortable working on control systems," Eli said. "I could take a look if you know where I can gain access."

"Remind me when we're leaving," Pat said. "I'll put in the order and you claim it - no point working for free. You'll have your pick of private jobs if you can repair robotic systems. But first things first, and that means getting you a look at the digs."

"Would we be the only people living in this whole tunnel?" Liza asked, sounding a bit daunted by the prospect.

"There are twenty homes on this stub tunnel, and only three of them haven't reverted to MarsCo for non-payment of utilities. That's our catch-all term for air, water, electricity, and maintenance," he added. "Of the three that are still officially occupied, two of the families took work at a facility in the North and haven't come back in years, and the other one is taken by a couple of brothers who went out to Titan but left enough units on account to keep up with the utility payments." He palmed the access plate next to the first door, which slid open with a slight squeal. "Dry rust. You get some corrosion from the moisture condensing out of the air if you leave steel doors too long without using them."

Henry darted into the apartment while the realtor was talking. "It's all empty," he reported in disappointment.

"All of these homes would have been cleaned out when they were officially reverted to the MarsCo general pool. I remember working in this area for a couple of days emptying abandoned apartments when I was a teenager, but it might have been one tunnel over that way," Pat concluded uncertainly and pointed somewhere behind them.

"I'd like to hear a little more about how MarsCo came into possession," Eli said as the children began to explore the dwelling. "Do they hold a mortgage on every home, or can they take somebody's private property for any debt?"

"The utilities give value to what is basically just a hollowed-out space," Pat explained. "MarsCo handles all the tunnel excavations and airlock installations since keeping the burrow from decompressing is a matter of public safety. A boring rig fitted out with a hypersonic drill-face cuts through bedrock like butter and can hog out an apartment like this in a few hours. The main thing slowing down the process is the need to continually remove the rock dust. You can rent a boring rig yourself, but you won't save anything over paying MarsCo to handle it. The total cost of an excavation in either case is less than what you'll pay for a year's worth of utilities."

"But what about installing the plumbing, electrical fixtures, and ventilation? Is it all done by robots like on Earth?"

"No, and everybody gets the same plumbing, electrical fixtures, and ventilation system," Pat said. "There were a lot more people living in this area when the spaceport and the atmo station were under construction, but once they were up and operating, those workers moved on."

"Everything we've seen since arriving is part of a temporary work camp?" Eli asked in astonishment. "It all seems so permanent."

"It takes hundreds of skilled workers with robots around twenty years to build an atmo station. There's no point in my trying to describe it when you'll spend a MarsCo day working there soon enough, but you can think of an atmo station as a machine the size of a small city that's built from local materials. It starts with a fusion plant to provide power for the iron smelters, and the scale of the furnaces and holding tanks is such that they have to be built on-site in the cavern. The excavation work required makes all of the tunnels you've seen look like so many pinpricks in rock."

"What's an atmo station?" Liza asked.

"An atmospheric station," Pat said. "There are over eight hundred of them operating on Mars, and the goal is to build a thousand. Their first function is to make our caverns livable, but the long-term goal is creating a breathable atmosphere for MarsCo."

"It's just a lot of empty caves," Henry reported as he came out of the back rooms. "They didn't paint the walls."

"Do you see those little holes drilled in a line just below the ceiling?" Pat asked him. "Families that move frequently to work on major infrastructure projects prefer wall hangings to painted surfaces. It's a way of taking their home with them."

"Like the nomadic cultures on Earth who moved with their flocks to fresh pasture and kept their wealth in rugs. We learned about them in history."

"That's a good comparison, and I remember a section about the herding cultures of Earth in my history courses."

"I don't like it," Liza announced. "It doesn't feel like a place to live."

"That's because it's empty," Pat told her. "If I'd had more notice, I would have staged it for you. It's hard to imagine what it would be like living in a place that's just empty rooms. Did you bring any furnishings from Earth?"

"A whole container load," Eli told him. "I couldn't believe how inexpensive it was, but there's not as much trade between Earth and the colonies as there once was, and the transportation infrastructure was built for much higher capacity."

"And built to last." Pat led them back out into the tunnel. "Did you know that Earth hasn't built a new interplanetary container ship or passenger transport in centuries? They stopped after the first Ark was launched." The tall Martian shook his head. "The interstellar Arks were the pinnacle of Earth's civilization. It's hard to believe you gave up the whole program because Alpha concluded that it was unnecessary."

"After centuries of pouring resources into space, Alpha decided to call it quits. But it wouldn't have been possible without him to start with. He provided the reactionless drive, and a thousand years later, we still don't know how it works."

"Nobody has heard back from the Arks," Henry added.

"Earth has the only orbital antenna array with enough gain to pick up messages from light years away, and Alpha may have stopped listening when his priorities changed," Pat said. "My grandfather told me that MarsCo investigated the feasibility of building our own orbital array of high-gain antennas, but they decided that the resources couldn't be spared just for the sake of curiosity."

"Curiosity?" Henry's voice cracked with indignation. "What could be more important than pioneers who have traveled to the stars?"

"Our families right here at home," Pat said, palming open the lock on another apartment. "Even with reactionless drive powered by fusion, it takes multiple generations for a ship to travel between star systems. If they run into trouble, there's nothing at all we can do to help, and if they discover a world that's suitable for colonization, we'd have to drop everything and spend the next hundred years building an Ark if we wanted to send our grandchildren to join them. Except it would be our great-great grandchildren's grandchildren by the time they arrived. And what would be the point? So much time will have passed that the colony will either have grown to the point that another hundred thousand people are barely noticeable, or it will have failed, and the trip will be in vain."

"Arks carried a million people," Eli said.

"We don't have the resources Earth did when it was building the Arks. If we constructed one in Mars orbit, a tenth of the size would probably be a reasonable goal. The original Arks were built with metal mined from the moon and the asteroid belt, you know. The reason they took so long to complete was their sheer size, and for a few hundred years, there were always several under construction at the same time."

"It's exactly the same," Liza announced after two steps into the next apartment. "I don't like it."

"Does MarsCo build its own spaceships?" Henry asked.

"Only when we need to, which is rarely," Pat said. "There's a large space engineering department at the U, but like Earth, we build modular spaceships with replaceable fusion cores. Unless a meteor gets through the screen or the ship botches a docking or landing sequence, there's not much to go wrong."

"I thought space was dangerous."

"To people it's dangerous. A small mistake on a spacewalk can kill you, and there are lots of accidents that can take place in Zero-G. But things that kill people rarely destroy spaceships beyond repair. It's not like sailing the oceans on Earth where a bad decision could sink the ship."

Eli cleared his throat. "Getting back to Mars for a minute. If all of the apartments on this corridor were excavated out of bedrock at the same time and are essentially identical, what are we talking about for price?"

"As the kids have pointed out, it's a cave with plumbing, electricity, and ventilation," Pat said. "The excavation work was already paid for, and the claim has reverted to MarsCo. Other than my commission, which is currently up to," he glanced at his wristcomm, "eighteen minutes and seven seconds, the only cost is what you put into it, plus the regular payments for utilities."

"And just how much will sewer, water, air, and electricity run us?"

"There's a five-minute per month maintenance charge for connectivity to each service, and other than that, it's all based on actual usage, as measured by flow sensors."

"You mean we get charged every time we flush the toilet?"

"Precisely," Pat said. "That was a pun if you didn't catch it."

"I'm just trying to get a rough idea of the overall housing cost," Eli said. "Is paying for all of those utilities going to take a week of work every month?"

"Nowhere near that. Four hours might cover it for your family. The electricity is generated by fusion and is practically free, and that means that running the pumps and purification plants is also inexpensive. It's the water and the air that make up most of the cost, and to be blunt, that's mainly to discourage waste. How do they handle housing on Earth?" Pat inquired as he palmed open a third door. The children rushed in to explore.

"My practical experience is limited to the community where I grew up, which wasn't typical for Earth," Eli said. "In most places, you can get apartments in linear cities in return for a percentage of your income, even if your only income is the basic dole that Alpha pays everybody."

"And in your community?"

"Our population is stable, and Alpha treated us like the crazy aunt in the attic. But we had to teach his standard curriculum in the schools, and of course, he monitors everything for the sake of alignment."

Pat took two steps back before saying, "It sounds like you were living with people who didn't want to be on Earth."

"Does that make us undesirables here?" Eli asked, surprised by the other man putting a distance between them. "I can't recall anybody ever backing away from me in the middle of a friendly conversation."

"I wanted to see your face and my neck is getting tired from looking down at you," Pat said with a laugh. "Don't be surprised if you find yourself with a crick in your neck from looking up at me, though having just come from Earth, your muscles probably won't notice. And to answer your question, I learned enough about Earth in my schooling that I'd question the sanity of anybody who wanted to live there, so your being from one of the out-groups is a positive."

Four

"I feel bad about taking so much of your time," Faya told the tall teenager. "I'm sure you have places you'd rather be than teaching me about things you've known since you were a child."

"I'm on the clock," Zest said. "MarsCo has a program for absorbing immigrants, though you're the first we've had around here that I can remember. I earned a couple of hours last night doing the short course for immigration facilitators, and I learned that almost everybody who's come to Mars in the last century settles further to the south. Earth was at the very bottom of the list as a point of origination. We get more people from Ganymede, Titan, or any of the asteroid belt habitats."

"I'm glad you're getting paid. Will I be billed for your time?"

"No, it's a public service. Isn't your son coming with us?"

"It's just me and Liza today," Faya said. "My husband took Henry on a day trip just to see what it's like further south. It's not that we aren't happy here," she added hastily on seeing Zest's face fall, "I'd like to stay in this apartment until we get the children settled into their homeschooling and figure out how we're going to fit in. It seems to me that it will be easier to adjust in a small community than in a large city."

"That's my advice, and I won't charge for it," Zest said, leaning forward to help Liza arrange her new braid in the Martian style. "I'm not saying anything against the cities, but the only thing they have that we don't is more people. I guess if you like crowds it's okay."

"You aren't planning on going to university, I mean, U, and meeting new people?"

Zest scowled. "I'd rather just work, but my family are pushing me to go, and all my sibs went. I'll probably start some courses from home and see if there's anything that interests me enough that I have to be on campus. I don't see the point of moving to Muskville just to go to parties. We have parties here, and I'm getting my own place soon."

Liza returned from checking her new updo in the mirror, her eyes shining, and asked, "Where are you taking us today?"

"We'll start with the local MarsCo office. It's where you can sign up for homeschooling, and it turns out there are also some required courses for adults who are immigrating. I wouldn't have known about that if I hadn't taken the immigration facilitator course. After that, we can go where you want, or I can show you the places I think are important."

"What would you choose?" Faya asked as she and her daughter followed Zest out of the apartment.

"Everybody has to eat, so I'd start with the canteen. They have the best bakery and the freshest veg since they go through everything so quickly." Zest noted their blank faces and looked surprised. "You don't have canteens on Earth?"

"Is it like a robot thing?" Liza asked. "Daddy works with robots, so he'd know."

"I've never heard of them," Faya added.

"Every community on Mars has at least one," Zest said. "It's the MarsCo cafeteria chain and it's great. Some families rarely cook because the takeout from the canteen is better, and since everybody has worked there, it's almost like eating from your own kitchen. Some of the fancier entrées and baked goods come from a regional commissary through the delivery tubes, but there are always local specialties. My mom is the omelet queen."

"Are delivery tubes the same as tunnels?"

"They're much smaller and they're strictly for MarsCo use, mainly the canteens. The delivery tubes are drilled with plasma beams so the walls are like glass, but you couldn't fit into one. And they're all point-to-point, from the regional commissary direct to the canteens or MarsCo utility sites. It would take you over an hour to get to the nearest regional commissary in a dull, but it only takes a couple of minutes for a capsule of baked goods to make the trip in a tube."

"Are we going in a dull this morning?" Liza asked. "It felt like floating."

"It is floating, on a magnetic field," Zest explained as she led them into a large pedestrian tunnel. "The delivery tubes work the same way, but with a much smaller rail and magnets. There's an airlock at both ends because the air is pumped out of the tube to remove wind resistance. My brainiac brother says they could deliver a capsule in seconds if they wanted to, but they speed up and slow down gradually so the food doesn't get smooshed."

"I see the blue line on the wall, but what does it mean?" Faya asked.

"Blue lines connect to yellow pedestrian tunnels in any burrow. The unmarked tunnels are the smallest ones, and they always end in a housing cluster on one end and a yellow tunnel on the other."

"Are there any parks? Places that the children could play outside?"

"Outside?" Zest asked. "They'd need to wear oxygen masks and T-suits for that. But we have the inside park on the blue, and it uses sun tubes rather than artificial lighting. Most people try to spend a little time there every day if they don't get sun elsewhere. There are lots of benches, and when the flowers are in bloom, it smells like perfume."

"Henry read everything he could find about Mars before we came," Faya said. "At breakfast, he told us there were canyons with glass roofs to keep the air in. Is there anything like that around here?"

"Oh, you mean the Valles Marineras, where the original emigrants from Earth settled. We're pretty far away, and it's mainly Oldtimers who live there. But parts of the canyon are so deep that the sun only gets down there when it's directly overhead, which never lasts long. I went to one of the fully enclosed sections on a family vacation when I was a little kid, but all I remember is the ice and the cold. We went skating."

"I want to go skating," Liza said immediately. "I packed my skates, and I can do spins."

"I forgot that you brought a whole container from Earth," Zest said. "We should probably go by the spaceport later just to make sure they set it aside so you can get access if you need anything."

"I intended to ask about that," Faya said, though her eyes were drawn to a display on the tunnel wall that was promoting some event that featured circus performers. "The holographic projection system your relatives left behind is stunning, even if all it does is project an aquarium."

"The fish looked so real, but my hand went right through them," Liza added.

"That's just one channel out of thousands," Zest told them with a laugh. "It works on voice control. You just have to say, 'Change Channel,' and tell it what you want."

"Mars has thousands of channels?" Faya asked incredulously.

"Most of them are like the aquarium, and there are lots of nature scenes from Earth that repeat in a loop. But the MarsCo all-news channel is good if you want to keep up with what's going on, and there are a bunch of sports channels. The homeschooling lessons are delivered by hologram, though you get reading materials on your tablets. There are projectors in the bedrooms that you might not have noticed because the equipment is in a cubby, and it's traditionally covered by a one-way mirror. Lots of people run a hologram that looks like a window, and you can pick whether you want to be in the country, the city, the season, anything you can imagine."

"The mirror in my room is as big as I am," Liza said.

"That's the one," Zest told her. "Ask your wristcomm to turn on the projector. It can also play music. You must have the same thing on Earth."

"Alpha operates all of the holoprojectors, but the community we lived in put an emphasis on live entertainment and playgroups for children," Faya explained. "We listened to music, but we rarely turned on the holo."

The tunnel began to widen into a space where small businesses like Dov's had shops in large shipping containers or had set up folding tables flea-market-style with all their goods on display. Zest stopped a few times to introduce Faya and Liza to people she knew, and then they arrived at glass doors opening on a large room carved into the tunnel's wall. "Here we are," she announced.

"There's no signage."

"Everybody who lives here knows what it is, and the only people who come are the ones that live here." Zest pulled open the left door, the first one on hinges that Faya had seen since leaving Earth, and led them in. The lights came on the moment the door opened, revealing a high counter with chairs vaguely reminiscent of bar stools, and a wall-sized display screen that was showing a ten-by-ten grid. "Hundred-day plan," Zest told them.

"But there's nobody here," Faya said. "Did we need to make an appointment?"

"You have one," Zest said, moving around to the other side of the counter. "Can I help you?"

"Can you - is this Martian humor?"

"I told you that I'm on the clock today working for MarsCo as your immigration facilitator. Let's see. You need all the starting homeschool materials, which include assessments you'll give the children to find out if they need to start back at the beginning, and I'm supposed to explain the hundred-day calendar to you."

"Maybe we could start with the homeschooling materials," Faya said.

"All right." Zest produced two white plastic boxes from below the counter and then added a grey box to the side. "One white box for each of the children, the grey is for you and your husband. All the holographic classes are delivered over the MarsNet, but the boxes contain a standard tablet for reading and writing, and you can watch lessons on it in two-D if you're somewhere without a holo system. The first time you use the tabs, you'll be asked to go through a voice registration process, and after that, you won't have to identify yourself when using any MarsCo systems because you'll always be recognized."

"And we really won't be going back to school?" Liza asked. "I didn't like getting up early every morning and having to sit still in class, but I miss my friends and Alpha."

"We'll talk about that later, sweetie," Faya said. "Is all of the schoolwork done at home? Are there tests at a central location, or group projects?"

"Yes, no, yes," Zest replied in order. "Pay is at a tenth of the standard rate for all pre-U studies, but it adds up over the years. Some kids spend six hours a day on coursework, so that's thirty-six minutes of earnings right there. But kids aren't allowed to buy anything that costs over an hour without parental approval until they're eight."

"I'm sorry if I sound dense, but did you just say that MarsCo pays the children for studying?"

"At a tenth of the regular working rate. If they go to the U, MarsCo pays them half the regular rate, but that includes food and housing if they want to live on campus. If they turn into professional students and continue for a second degree or a specialization, they'll earn straight time."

"We get paid for going to school at home?" Liza asked, her voice coming out in a squeak. "Henry isn't going to believe me."

"There's a token reader in each box to swipe in order to get paid," Zest said. "The system clocks you in and out automatically when you're watching holographic lessons, but you have to do it manually during study time. Some kids think it's funny to try to get paid for doing homework when they're taking a nap or something, but the system will figure out that you're falling behind on your projected performance, and then it will inform your parents."

"I would never cheat."

"Good to know. And I don't understand why, but the lessons for adult immigrants don't pay anything."

"That doesn't matter," Faya said, gathering up the boxes, and then on reflection, handing a white one to Liza to carry. "We're eager to learn everything we can about Mars. You said something about a hundred-day calendar?"

"Right," Zest said. "You'll find one on the wall of every MarsCo office. You can also get it directly off the MarsNet on any screen, or ask a holoprojector to display it, though you need a big space if you're going to show the whole thing and still be able to read the text. There's a different hundred-day calendar for every burrow because they figure commuting time into the available work." She came out from around the desk and pointed at the top-left square, which always showed the current day. "Yup. Orientation for new immigrants with an eight-hour limit, and you can see it's greyed out, which means it's taken."

"By you."

"Now you're starting to understand. And before I claimed the work, it was the second largest unfilled request in our burrow for today."

"I don't understand how we even rated high enough to appear on the board," Faya said. "I know that MarsCo runs the spaceports, the atmosphere plants, and all the utilities. And that doesn't include the canteens you mentioned. Don't they all need employees every day?"

"Any job that continues from day-to-day and is already claimed isn't listed, so that covers most of the work in a small burrow like ours. What's left is - " she checked the box again, " - babysitting little Kat while her parents go to dance class, a four-hour canteen catering gig, two hours of help for Bunny - she's forty and she broke her hip, so she's supposed to have help at home until it's fully healed - and the rest is just the open requisitions."

"Which are?"

"Oh, I keep forgetting that you're starting from zero," Zest said apologetically. "Every burrow has an open requisition for ongoing projects like mining. If you're willing and able to go out and work on the surface, or if you train to maintain any of the infrastructure or utilities, you can work up to six days a week for MarsCo and never get a normal job."

"And there's no difference in pay rates for any of this work?" Faya asked.

"Why should there be? I've babysat for Kat, and three hours took more out of me than working all day on the surface or in the canteen kitchen."

"And why is babysitting a MarsCo job at all?"

"In a bigger burrow, it might not be, but in smaller places, they let anybody list work on the board. MarsCo just acts as the middleman for the payment. You could also manage it through your wristcomm and token."

"I still can't believe that taking me on an orientation tour was important enough to make the list," Faya said, skimming ahead through the squares to see what other sort of work was listed. "Window washers? I have yet to see a dirty window on Mars."

Zest laughed. "Work with me the day after tomorrow and you'll see enough dirty windows for a lifetime."

Liza looked up from rummaging through her homeschooling box and asked, "Can I come?"

Faya opened her mouth to answer, then shut it and looked at the young immigration facilitator.

"You're too young to go outside without supervision, and we'll be too busy cleaning windows to watch you," Zest told her. "Besides, don't you want to get started on your schoolwork?"

"Do we have art classes?"

"There are always art workshops you can take. The options change from cycle to cycle depending on who's available to lead, but when I was your age, we had in-person art and music three times a week."

"In a real school?" Liza asked.

"Usually in the park. I'll take you there now and show you where some of the workshops meet."

"And you said it has sun tubes," Faya said. "You've mentioned them before, but I didn't ask because I can sort of guess from the name."

"Sun tubes are a way of getting natural sunlight underground without windows," Zest explained. "The problem with windows is that if you aren't right at the surface, you won't get much light unless the sun is directly overhead. The tubes are reflective on the inside and use a lens with mirrors on the surface, so they can gather light from a larger area and concentrate it."

"My brother Henry can start a fire from sunlight with his magnifying glass," Liza said proudly.

"It's kind of like that, but without the burning. At the inside end of the tube, there's another lens that spreads the light out. I've helped install sun tubes in people's homes," Zest continued. "If you're good with a drilling rig, you can make the walls of the hole come out so smooth that all you have to do is close up the ends, pull a vacuum, and run the plasma-assisted chemical vapor depositing system to plate it with aluminum and - sorry. I'm getting too technical."

"It's fascinating though," Faya said. "It sounds like you've tried your hand at everything at one time or another."

"And why not? I'm nine, and I've been working helper gigs since I was six. My dad always says that the only way to find out whether or not you like a job is to try it."

"Henry is almost seven in Martian years. Does that mean that he'll be starting with helper gigs?"

"Some kids just pick one thing, like working on a farm, and stick to that all through their schooling. Keep in mind it's not a lot of hours," Zest added, "and there's usually a two-hour minimum when you show up for anything, which uses up a week's commitment in one shot for young kids."

"I suppose that makes sense," Faya said. "Anything less than two hours and the parents would spend more time getting their children ready for work and bringing them - no?"

"I don't know what it's like on Earth, but on Mars, a four-year-old is expected to be able to navigate the tunnels to anywhere in the burrow. Maybe when you live outside it's more complicated because there's so much more space."

"Oh, look at the pies," Liza said, pressing her nose up against the display window of the canteen. "Can we buy one?"

"We'll stop on the way back from the park," Faya said. "There's no point in carrying it with us longer than we have to."

"The park is right up here," Zest said. She led the way to a large sliding door. "The space is so big that they put in an airlock, just in case a marsquake opens up a fissure and there's a leak to the surface. And I need to show you the emergency air stations."

Liza ran through the doors, perhaps thinking that the sooner they visited the park, the sooner they could return to buy a pie, but she had to wait for the adults to enter before the airlock cycled through. When the inner doors opened, she couldn't hide her disappointment, "It's just a park, and the grass looks funny."

"I think it's lovely," her mother said, looking around at the sculpted shrubs and trees. "It's more like a fancy garden than a park."

"They have to do a lottery to give out work assignments here since so many people want them," Zest said, stretching her arms up toward the ceiling. "Doesn't the sun feel good?"

"But they're just lights," Liza said, squinting upwards.

"Don't look directly at the sun tubes or you'll be seeing spots in your vision for hours," Zest warned her. "Over there's an art workshop meeting in the picnic grove near the brook. Do you want me to introduce you?"

"Can we just go and watch?" the girl asked, suddenly shy.

"But maybe you'll be in this group," Faya said. "I think it would be fun to meet them and see what they're doing. From here, it almost looks like they're making mud patties."

"Sculpting," Zest said. "But you have to make the clay first because it's not naturally occurring on Mars. It takes a lot of ground water and organics."

"Are you sure it's okay to cut across the grass?"

"That's what it's here for, and it's pretty tough stuff, but the park rules prohibit organized games. If you want to play a sport, there are fields attached to the gym complex, but the playing surface is the same hard foam they use in the professional leagues - not natural."

"Look, Mommy," Liza cried in excitement. "It's a lizard."

Faya examined the rocky mound that her daughter had chosen to climb over rather than walk around, and sure enough, a large blue lizard was sunning himself on a flat reddish rock. A smaller lizard was just visible at the edge of a crevasse between the stones and was keeping an eye on the human interlopers.

"They look just like the lizards at home, except for being blue," Faya said. "Is it an adaptation to Mars?"

"I don't know," Zest said. She grinned when she saw the look of surprise on Faya's face. "Did you think I was a brainiac or something? I wouldn't have known half of what I told you this morning if I hadn't crammed that course for immigration facilitators last night. I'm really bad at nature stuff in general, and I stopped taking biology courses when we got to dissecting a frog."

"What's dissecting?" Liza asked.

"It's learning about what's inside living things that makes them work," her mother said. "Look. Some of the boys in the art circle are your age."

The would-be sculptors, a few of whom were younger than Liza, and the oldest of which was almost Zest's age, had noticed the approaching group by this time. One of the smaller boys dropped the ball of proto-clay that he was kneading, wiped his hands on his pants, and ran to meet them.

"You're the new one," he said, addressing himself to Liza and ignoring the adults. "I'm Gart and I'm five."

"Liza. I'm ten, I mean, five in Martian years."

"What other kind of years are there?"

"Earth years, I guess," the girl said, looking to her mother for confirmation.

"Never heard of them," Gart said. "Are you joining our circle? Today we're just making clay, but on Friday, Millie is going to let us throw it at a wheel."

"That sounds messy," Liza said.

"It's not that kind of throwing, Gart," Zest told the boy, with whom she was obviously acquainted. "The word means something different in pottery."

"Oh." Gart looked crestfallen for a moment, then he grabbed Liza's hand and tried to drag her toward the group. "Hey, you're strong," he said when she didn't budge.

"Earth muscles," Zest told him. "You're going to have to treat her nice or she'll pick you up and you'll be the one getting thrown."

Five

"Where's Henry?" Eli asked as he sat down at the kitchen table for breakfast. "Did he go out exploring?"

"He's still in bed," Liza reported cheerfully. "He says he's never getting up again."

"What?"

"I think it's about the home-schooling assessments the children did yesterday," Faya said, putting a bowl of oatmeal in front of her husband. "There's butter if you want it, and the orange juice is fresh from the farm."

"It's perfect as is," Eli said after a quick taste from the tip of his spoon. "Henry didn't mention anything about a problem with the assessments last night when we talked before bed. In fact, he said that he's already at the top level for math, and he can start taking early math and computer courses from the U as soon as he finishes the homeschooling requirements."

"He failed history," Liza said. "We found out this morning when we turned on our tablets. He's in the beginner course with me."

"It seems unfair," Faya said, taking the seat next to her husband and warming her hands on her coffee mug. "Henry worked so hard at history back home. Some of it must be relevant. What sort of questions did they ask?"

"Lots of Martian stuff." Liza displayed her empty bowl and then reached for the piece of the canteen apple pie that her mother had made her set aside until after she finished the oatmeal. "I didn't know any of it. And the Earth questions didn't make sense."

"What do you mean?" Eli asked after another spoonful of oatmeal.

"Questions about artificial intelligence and freedom, except it was all kind of backward, like Alpha was bad for us."

The parents exchanged a look, and then Eli said, "I'll get Henry as soon as I finish this."

"I can do it," his wife said.

"No, it's better I do. He took it hard when I started explaining how alignment had gone wrong. Alpha doesn't teach anything about alignment and presents himself as humanity's greatest achievement."

"It's boring history, not art," Liza said. "I mean, who cares?"

When Eli entered Henry's bedroom, the boy was pretending to be asleep, but the unnatural rigidity of his body gave him away.

"Come on, Henry. I know you're awake. Get up and have breakfast so you can start your lessons. You told me you were looking forward to it."

"I was looking forward to doing the top level of math," Henry replied without hesitation. He turned toward his father, a tragic expression on his face. "I don't care if Alpha was teaching us history that made him look good, everybody does that. It's not fair that I have to be in the same class as Liza."

"But you're older and a better student than she is, so you'll finish it long before her," Eli said. "I bet she'll be asking you for help all the time with things she doesn't understand. From what your mother told me about the way MarsCo works, you'll probably get paid for tutoring her."

"How can I finish before her if we're both sitting in front of the same hologram?" Henry demanded grumpily.

"You can watch alone in your room if you want to, but you know that your sister will be disappointed. I'm sure there will be plenty of reading assignments, and you'll end up running way ahead like you always do," his father said. "Besides, how do you think I feel about having to take the same course as my children?"

Henry sat bolt upright in bed. "What?"

"Your mother and I took an assessment last night for adult immigrants which focused on Martian history and MarsCo civics. Our course advisor strongly suggested that we take the beginners history course."

"For children? But you're an adult."

"It seems they don't look at it that way on Mars," Eli said, and he laughed despite himself. "On the bright side, the advisor said that due to our special circumstances, your mother and I will get paid regular time when taking children's courses, and how could I argue with that?"

"Is your adviser a person or an artificial intelligence?" Henry asked, getting out of bed, and pulling on his pants.

"You know, I'm not sure," his father said. "It might have been artificial intelligence, or it might have been a person. We only communicated by text. I'll have to ask."

"But what if it lies?"

"Then I'll get the wrong answer. Your mother and I are both eager to start work and find out if Mars will be suitable for our community. We won't be allowed to participate fully in MarsCo until we demonstrate a basic understanding of the same courses you kids are taking."

"That's not fair either," Henry said, pulling on his moccasin-style shoes. "If I was an adult, I wouldn't agree to take children's courses."

"The important thing is the information," his father said. "Historical facts are the same whether you're a child or an adult. I'm looking forward to filling in quite a few holes in my understanding of how Alpha took over, not to mention learning more about the current state of Mars and the other colonies."

By the time Henry finished his breakfast, the rest of the family had rearranged the Martian furniture around the default projection area for the holographic system in the living room. Faya was surprised by how light the couch and chairs were, even in the reduced Martian gravity. After a little wrestling with the slipcovers, she found out that the furniture was inflated like airbeds.

"I hope they don't leak down and need refilling all of the time," she said to her husband.

"I can't imagine why they would," Eli said. "The only seams I saw were fused together, so the leakage should be limited to diffusion through the plastic, which can be held to almost nothing with the right coatings."

"Why didn't we have air furniture on Earth?" Liza asked.

"Maybe because we weighed three times as much, or because the temperatures in people's homes varied more than they do here. Temperature changes are tough on anything inflated with gas because of stretching and shrinking."

"I'm ready," Henry declared, plopping himself down on the couch with a determined look on his face and the stylus for his tablet gripped in his right hand. "But if they try to teach history with cartoon characters, I quit."

"Let's not start by looking for problems," his mother hastened to say before Liza could come up with her own conditions for participating in the lesson. "I'll tell it to start." After a quick glance at the single laminated card of instructions that came in the children's home-schooling kits, she added, "Please begin the first history course."

A holographic projection of a slender elderly woman appeared, and the instructor nodded as if she could see the students. "Thank you for coming. First-year history requires reading at course level seven, and students who haven't met the requirement cannot receive credit for completing this course. Today I'll start with a ten-minute introduction to how our civilization on Mars reached its current state, and then I'll ask you to read the first lesson of the course text before continuing. I'm recording this lecture in the year five hundred and forty-two on our Martian calendar, which means that just over a thousand Earth years have passed since colonization began."

As she spoke, the hologram grew darker and darker, until she faded from view and was replaced by a slowly spinning Earth, which in turn receded until it was barely a speck. But as the Earth shrank, other celestial bodies came into view, starting with the moon, then Mars, then Venus and Mercury, before the sun crept into the hologram and the outer gas giants appeared.

"This simplified view of our Solar System shows the planets all in a line, but the true situation is more complicated, as you'll learn in your science courses. For now, it's important to note that while Mars is the closest planet to Earth, it's still over fifty million kilometers away when the planets are nearest to each other, which is a very long distance to travel. Humanity's initial expeditions to Mars all took the form of unmanned landers, or robots, which explored the Martian surface and sent the information back to Earth."

The black of space faded out and was replaced by an artist's conception of a spacecraft making a landing on the dusty surface of Mars, its fall cushioned by giant balloons. The sides of the lander unfolded, and a rover rolled out, its solar panels deployed to catch the sunlight.

"Years passed, and eventually, manned missions were sent to Mars, but the economics of spaceflight powered by rockets and gravity slingshots delayed the start of colonization. Then, in the span of a few short decades, several very important developments took place."

"What's a gravity slingshot?" Liza interrupted.

"Pause course," Faya instructed the holographic projector.

"It's a bit complicated to explain, and it's probably not important for what she's trying to teach," Eli said. "Let's try to watch straight through, and then we can go back and see what questions you have."

"The vocabulary seems a bit advanced for a starting course," Faya said. "I assumed that the seventh reading level meant the same as seventh grade."

"The test put me on the seventh reading level," Liza reminded her. "All those books I read on the trip from Earth made me super smart. I can wait and ask later."

Faya considered her daughter's words for a moment and then instructed the projector to continue.

The hologram of the instructor reappeared, but now she was holding a balloon in one hand, the neck pinched closed. "Like balloons, rockets push themselves forward by forcing out a reaction mass," she said, and then let go of the balloon, which zipped around the hologram in a random flight before quickly exhausting the gas and dropping to the floor. "Just getting off the surface of the Earth requires a tremendous amount of fuel, and carrying that fuel adds to the weight that must be lifted in the initial stages. Artificial general intelligence on Earth perfected portable fusion reactors that supplied steady power over long periods of time, and soon after, the superintelligence who named himself Alpha gave us reactionless drive as a practical solution for spaceflight."

Now the hologram displayed enormous cylindrical spaceships lifting slowly off the surface of the Earth without any sign of motive force, and then the view zoomed out to show a massive orbital shipyard where construction of even larger vessels was underway.

"Robotic work crews were sent ahead to Mars where they began mining and smelting operations to provide materials for large-scale infrastructure. A fully robotic factory producing superconducting cable was set up with the goal of creating a new Martian magnetosphere to deflect the solar wind. Other robotic crews began roofing sections of the Valles Marineras, and our real history begins with the first colonist landings on Day One of Year One."

"Pause course," Faya said. "Did that make sense to you?"

"It's pretty much the same as what we learned in history back home to this point," Henry said. "It took a lot of years to produce enough superconductor to go all the way around the planet, but smaller areas could be shielded from solar radiation separately, so the colonists didn't wait until it was finished."

"I thought you said we wouldn't stop the hologram again before the end," Liza said accusingly.

"Sorry," her mother said. "Continue lesson."

"The centuries following the discovery of reactionless drive led to the emigration of hundreds of millions of people from Earth, with nearly half of the total coming to Mars. Work was begun on making the surface of our new home habitable, and the Mars Cooperative, styled after early farm cooperatives on Earth, was established to manage the unprecedented project of creating an atmosphere."

The holographic projector displayed images of underground fusion plants and enormous industrial complexes that were reminiscent of old oil refineries on Earth but on a much larger scale. Rugged-looking spacecraft powered by reactionless drive were shown towing icy asteroids into low orbit, and in some cases, shattering them with explosives before the fragments rained down on the thin Martian atmosphere.

"The first goal of the Mars terraforming project was to create atmosphere generation stations which employ chemical processes to extract the required gasses from Martian minerals," the historian continued. "The stations also use frozen ammonia brought to the surface by harvesters that range from the nearby asteroid belt to the rings of the gas giants. Alpha supplied many of the technical innovations required to accelerate the process, including technology for safely landing ammonia-rich ice on Mars for use by the atmosphere generation plants."

"Pause course," Faya instructed again. "I'm sorry, but I keep getting the time confused. Is she talking about Earth years or Martian years?"

"Martian years," Henry answered immediately. "If it was Earth years, the atmosphere would be almost finished. Alpha told me that after a thousand years of work, trying to breathe on Mars was like being on top of Mount Everest, with the cold and the thin air."

"I don't understand, but I'm waiting until the end," Liza said pointedly.

Faya reached over and gave her daughter's braid a playful tug before instructing the projector to continue.

The holographic images of vast engineering projects in progress were again replaced by the elderly woman, who smiled apologetically. "I'm sorry if that was heavy on the technological mumbo-jumbo, but it's difficult to begin the history of Mars without referring to the principal purpose of MarsCo. After a few generations, most people living on Earth lost interest in the slow-motion progress on Mars and turned their eyes toward the stars. As the colonization of our Solar System lost momentum, Earth's focus shifted to developing interstellar colony ships, more commonly known as Arks."

Now the hologram displayed several truly gigantic cylindrical ships under construction in Earth orbit and then shifted to the interior of a vessel being prepared for departure. An end view of the cylinder showed that it had already been spun up to provide weight nearly equivalent to that on the surface of Earth for the inhabitants, and then the hologram was replaced by a cross-sectional drawing and the lecture continued.

"The standard Ark design featured eighty concentric cylindrical decks, providing tens of thousands of square kilometers of living and working space, complete with agricultural decks and factories that were primarily dedicated to producing food and recycling wastes. Initial demand to join the Arks was so high that a lottery system had to be established to distribute the places. Each Ark began its multi-generational journey with a million inhabitants in the ship's company, though strict population control measures were required."

The hologram shifted to a breathtaking scene of a giant Ark slowly moving away from the elliptic plane of the solar system on its way to a promising star system light years away. For almost thirty seconds, the ship was shown shrinking, shrinking, until nothing but a dot of light remained.

"Alpha began evolving his own ideas of what was best for humanity, and a little over fifty years ago, he shut down the interstellar exploration program and quietly began scaling back support for the colonies within the solar system."

"Pause course," Henry said and then flushed in embarrassment when he remembered they'd agreed to play it all the way through. "I just wanted to say before I forget that she makes it sound like Alpha was controlling us, rather than serving us."

"Alpha decided that Earth was squandering its resources on space and that by eliminating the interstellar program, he would be better able to serve the population," Eli explained. "I never believed that to be the whole truth, because with robots building robots, most resources aren't an issue."

"Continue," Liza instructed haughtily, causing the rest of her family to laugh.

"Trade with the rest of the solar system was maintained, with Earth exporting luxury goods, pharmaceuticals, and technological innovations created by Alpha, in return for precious metals and rare elements useful in manufacturing. But since the Ark program was terminated, news from the rest of the solar system is rarely seen on Earth, and stories about colonists no longer appear in fiction or other entertainment media."

"It's like the Fermi Paradox," Henry chipped in.

"Pause," Liza said. "The what?"

"We know that the galaxy is full of stars that have planets where life could start, but why haven't we ever picked up alien radio transmissions? One of the reasons could be that all the aliens have superintelligences like Alpha that just aren't interested in the rest of the galaxy."

"I think she was getting near the end of the summary," Eli said. "Shall we watch the rest?" Nobody objected, so he said, "Continue course."

"With a population of almost two hundred million, Mars serves as the center of the loose confederation of human colonies on the moons of the gas giants and in the habitats of the asteroid belt. MarsCo barters our produce, manufactured goods, and access to higher education in return for iceteroids and ammonia-rich asteroids. The current atmospheric pressure recently passed 250 mm of mercury at the surface, about the same as that of Earth's highest mountains, but oxygen masks and thermal suits are still needed for working outside. In short, we are well on the way to our goal, and in the coming centuries, we, the new Martians, will reclaim the surface of our planet."

The woman faded from the hologram and was replaced by a large block of text with the heading, "Continue with Lesson Two of Mars History in this projection or read on your tablet."

"Close lesson," Faya said, and the hologram disappeared. "I think I have more questions than answers after watching that."

"I want to go outside," Henry announced.

"Me too," Liza said.

"We don't have oxygen masks or, what else did she say was needed?" Faya asked.

"Thermal suits," Eli said. "She didn't give the temperature, but I imagine it's cold if the atmosphere is the same as on Earth's highest mountains, since they're all covered with snow."

"Zest will know where to get us clothes," Henry said confidently. "And seeing the surface will help us learn history."

"One thing at a time," Faya said. "Do you all know how to find the history text on your tabs?"

"Henry showed me," Liza said. "But I didn't want to read ahead and spoil the hologram."

"In history class back home, Alpha taught us that manual labor is a waste of human potential," Henry said. "That's what robots are for. The whole point of being human is to experience life and share it with him, so he can do what's best for us."

"I imagine that's why MarsCo thinks we all needed to take the beginning history course," Eli said. "Alpha teaches an Alpha-centric view of the universe."

Six

Zest selected a slice of breakfast pie from the canteen carousel, prepared a coffee with so much cream that it would have made a good bedtime drink, and confirmed payment via her wristcomm. It took her a few seconds of scanning the crowded seating area to spot her uncle with the immigration field agent from MarsCo.

"What do you think of the Bookers?" the agent asked with no preamble as Zest took the seat next to her uncle.

"They're funny," she replied without hesitation. "Maybe everybody from Earth is funny, but they're the first I've met."

"Do you think they're hiding anything?"

"Everybody is hiding something. I don't think they're spies if that's what you're getting at."

"They're always asking questions, but that's what you'd expect from people who don't know a thing about Mars," Pat added. "Eli seemed pretty uncertain about what he was looking for in terms of real estate, but moving from the surface of Earth to an underground apartment on Mars is a pretty big transition. He seemed like a normal enough guy to me."

"And the little girl is full of energy," Zest said after swallowing a bit of pie. "Both of the kids bounce when they run, but the parents sort of slide along when they walk, as if they're afraid of losing contact with the floor."

The field agent nodded as if that's what he'd expected to hear and leaned back in his chair. "Let's synch comms so you can contact me without delay if you notice suspicious behavior," he said, and without waiting for them to agree, tapped his wristcomm and said, "New Contacts."

Pat tapped his own comm and said, "Synch." Zest did the same, though it was clear she was unenthusiastic about being roped into what was starting to look like an investigation.

"Listen," the field agent continued. "It's probably nothing, but we haven't had a young family from Earth show up here in a very long time. Alpha doesn't keep Earth's population up to date about the progress on Mars, so Eli and Faya knew next to nothing about conditions here when they booked passage. Who does that with children?"

"Maybe they had problems at home they needed to get away from, like their kids being bullied in school," Zest said. "I remember from an imported drama that their schools are competitive."

"It could be something like that," Pat said slowly. "I had the feeling a couple of times that Eli was about to tell me something and then pulled back. Maybe everybody from Earth learns how to keep their thoughts to themselves."

The agent pondered this suggestion for a moment before replying. "You could be onto something there, but they'll loosen up with time as they come to trust you."

"Because we're such nice people who would never spy on them and report to an immigration field agent," Zest said sarcastically. "I didn't even know MarsCo had field agents until Uncle Pat messaged me this morning."

"Somebody has to be responsible for security, and it should come as no surprise to you that we see Earth as a potential threat," the field agent said. "We have good relations with all the colonies cemented, by mutual trade. Earth doesn't need our business."

"But where's the threat? I thought nobody from Earth traveled beyond the moon resort because they don't like being more than a few seconds of radio delay away from Alpha."

"It's been forty or so human generations since Alpha introduced reactionless drive, but even with his explanations, there's not a living scientist who has a clue how it works. Alpha lets out new tech in dribs and drabs, like improvements to the holographic systems, but it's clear that he keeps most of what he learns to himself."

"As long as Earth's whole population isn't interested in moving to Mars, I don't see the problem," Pat said.

"I'm taking Faya outside for her first MarsCo workday tomorrow," Zest said. "Why don't I just ask her why they left Earth? I would have asked already if I'd been more curious, and now I am."

"Has the husband worked a MarsCo day yet?" the agent asked.

"I'm bringing him to the atmo station this morning for evaluation," Pat said. "Eli has a background in robotics engineering, though who knows how the current technology on Earth compares with what we use. It's a bit surprising that he was trained as an engineer at all. Alpha can't possibly need human help with robots."

"It's all part of the alignment process. Alpha likes keeping some human professionals working to learn about how well they understand new technologies." The agent gathered the last wedges of pancake on his fork. "I don't show your having registered as an immigration facilitator, though maybe you should."

"Taking Eli to the atmo station is off the clock. He asked how to get there, and I told him I was going that way today. In fact, I should head over there now."

"What business could take you in that direction?" the agent asked as the taller man rose from the table. "Atmospheric stations are always isolated for safety reasons."

"I'm beginning to think you do the job you do because you're naturally suspicious," Pat said with a wry smile. "I'm headed to Muskville, so any way I go includes a minimum of one transfer. The atmo station has good service because it doubles as the regional repair depot for robots."

"See you Friday at dinner," Zest called after her uncle, and then turned to the agent. "I can't believe you asked him that. What kind of work do you do when you aren't checking up on immigrants?"

"You've got a nice little burrow here, everybody knows everybody, and I doubt there's been a serious crime in your lifetime. My regular job is with the police in Muskville, and when you get a few million people living in one place, there are always going to be problems."

"But why would anybody need to commit a crime? There's endless MarsCo work if you can't make it in the private economy. And what crimes can they commit anyway? You can't steal from somebody's token balance unless they approve the transaction."

"Believe me, plenty of people try," the agent said while attempting without success to scrape up some of the syrup remaining from his pancake breakfast with the side of his fork. "We deal with a lot of fraud, and sometimes the circumstances are complicated enough to require a court to untangle who's telling the truth."

"My father always says that greed never ends well."

"Your father is right, at least most of the time. But imagine if I came to you and said I wanted to start a farm growing, I don't know, some exotic fruit imported from Earth, and I was looking for investors."

"I don't know you that well," Zest said immediately.

The MarsCo agent laughed. "You're a tough sell, but for the sake of argument, let's say you did, or maybe you were impressed by the holographic presentation I showed you, or maybe a cousin of yours said I was the smartest guy at the U. Then a couple of cycles go by without the farm coming to be, so you confront me wanting to know what happened to your investment. I tell you a story about how the excavation ran into problems, or the grow lights were back ordered from the factory, or that the seeds from Earth got held up in customs and are still in transit."

"What's customs?"

"A way for a government to generate revenue without doing any work," the agent told her. "My point is that some frauds stretch on for years. By the time the victims ask for arbitration, the units have all been spent. The more sophisticated scammers fabricate proof to show that they were engaged in legitimate business activities the whole time and just ran into a streak of bad luck. The crazy thing is that if they worked half as hard at a real job as they do at defrauding people, they'd come out ahead."

Zest took a minute to digest this information, and then she asked, "What happens to the people who refuse to work their MarsCo day? My parents always say that it never happens around here, and they hope that it never will, but the kids used to say that people who refuse to work get tossed out on the surface."

The agent laughed again and then coughed as his coffee went down the wrong way. "The kids in my burrow used to say the same thing, and while it's a gross exaggeration, there's a grain of truth. People who refuse to work their MarsCo day are exiled to the canyons, and what the Oldtimers do with them, I can't say for sure."

"But the Oldtimers are stakeholders in MarsCo like we are. They just aren't required to work MarsCo days because they don't use the same services and the canyon settlements predate the system."

"That's an exaggeration too, but it's true that they're less reliant on MarsCo than we are living in our burrows. And I'm not sure what would happen to somebody who still refused to work after being exiled to a canyon, but I wouldn't be surprised if a one-way trip to Earth was the only option to getting tossed out an airlock."

"Oh," Zest said, looking thoughtful. "No wonder my parents wouldn't tell me. What should I say if Faya or one of the children asks me?"

"I think your parents had a good answer."

While Zest and the field agent were finishing their coffees, Eli was asking Pat if he could spare a minute before they headed for the maglev.

"Sure. What's the problem?" Pat asked.

"I noticed a red light on the panel next to the refrigerator this morning," Eli told him. "It might have come on after we ran a load of laundry last night."

"It's probably the air filter. I'm surprised Zest didn't change it before you moved in."

"Why would the washing machine need an air filter? Doesn't it condense out the water from the sonic drying cycle like the machines on Earth?"

"The air filter is for the whole home," Pat explained as he followed Eli into the kitchen. "It's on the exhaust side, to limit the amount of particulate you send back through the ductwork. There are filters at the major junctions, and at the local air recycling node, but the best way to cut down on blockages is to stop the dust and particulates at the source." He glanced at the red warning light and then opened a skinny cabinet next to the sink that looked like it might be intended for trays. "Last one," he said, removing a large white filter in a transparent bag. "The automatic reorder will trigger as soon as it's installed."

"How do I open this?" Eli asked, examining the air intake above the warning light. "Is it spring loaded? Push and pop?"

"Press directly on the warning light. It's also a button."

The louvered cover of the air intake slowly folded out after Eli pressed the lit button, only stopping when it reached the horizontal. Eli slid out the filter, being extra cautious in case it was about to dump a load of dust in the kitchen, but the only sign that it had been used was the dirty gray color.

"The real trick is to be careful when you open the replacement filter bag so you can use it to return the old filter," Pat said, making sure that Eli saw the blue tab of the pull string. "If you don't pull hard enough, you'll tear the side of the bag, and if you yank it, the tab will come off." He demonstrated with a flourish, ending with a neatly opened bag and a tab with a length of thin string dangling from his right hand. "I usually take the new filter out and set it aside, and then work the bag over the old filter from the top."

Eli nodded, bagged the old filter with Pat's help, and installed the new one - flipping it at the last minute so the edge reading This Side Living Space was facing the louvers. "Do I lift the vent back into place or push the button again?" he asked.

"We aren't that addicted to automation. Just lift it into place until it clicks and the warning light goes out."

"And I bring the old filter to recycling?"

Pat shook his head and returned the bagged filter to the cabinet. "Usually there would be three more used filters by this point, but the home was unoccupied for so long that the air utility crew must have picked them up during the annual inspection. Funny that they didn't restock you with four new filters at the same time, but I suppose they have a shelf life."

"Do we have to schedule a visit?"

"The filter you just put in is good for two cycles, two hundred days, so they'll schedule somebody to drop off replacements during that time and pick up the old one. Assuming you're still here, you'll get advance notice, and if nobody will be home and you don't want them coming in, you can just leave the old filter in the tunnel next to the door and they'll do the same with the replacements."

"And they just charge our account?"

"It's part of the utility," Pat said. "You pay for it with the air, water, sewer, and electric."

"Let me just check that the kids didn't go back to sleep, and I'll be right with you," Eli said. "This homeschooling thing is new to them and we're trying to do it on the honor system."

"That's the only way it works in the end. Is your wife out shopping?"

"She went by the spaceport to check on our container. Even though the apartment has everything we need, we didn't know what clothes to bring in our luggage, and we erred on the side of cold. It would be a shame to buy all new summer clothes for the children when we brought them from Earth."

"You haven't bought weighted clothes yet?" Pat called after him. "I wouldn't put it off much longer. They're specially made so kids don't grow out of them too quickly."

A minute later, Eli returned, a bemused expression on his face. "They both looked annoyed that I interrupted their lessons," he said, following Pat out the door. "What was that you were saying about weighted clothes?"

"When kids here hit their growth spurt, they shoot up fast without putting on much muscle, so we make loose shirts with long tails and cuffs that can be unfolded. Trust me - when I was in my mid-teens, my mom was unrolling my pants legs and shirt sleeves another centimeter every other week."

"I'll believe it," Eli said, "and I'll tell my wife, but maybe it will be different for our children since they were born on Earth."

"I'm sure you could dig something out of the historical records, or comm a question off to the U," Pat suggested. "There must be somebody there who specializes in how living on Mars affects human growth, and they may even be excited to hear from somebody who has brought children here."

"I'll do that, but I didn't realize we were unique. There wasn't any problem booking passage on the container carrier. Getting up to orbit and making the rendezvous was more complicated because we had to buy space for ourselves on a shuttle that was bringing other containers up for shipment to Mars. It didn't have any passenger cabins, so we spent the whole trip in the crew's breakroom."

"No acceleration couches?"

"Some inflatable things," Eli said as they turned into the blue tunnel. "It wouldn't have worked in the old rocket days, but there's no need to attain escape velocity in a hurry when the motive force is reactionless drive."

"That makes sense. I've never been to space myself, but with the spaceport so close, we get visitors from the asteroid belt and the moons. They all say that spaceflight is about as exciting as sitting at home and watching a hologram of the stars that barely changes."

"That sounds about right. Once the novelty wore off, our kids were just impatient to get to Mars."

Pat nodded as they turned into a tunnel with maglev access, and holding his wristcomm near his mouth, said, "Main stop, atmo station." Then he stretched out his arm so that Eli could see the small screen too. "I don't know if Zest explained to you how the dulls work, but you always get a text confirmation of a request, along with the estimated wait time."

"She did, and I took a short trip south with my son the other day, but I don't understand how the capsules can show up so fast," Eli said. As if to prove his point, a dull slid to a silent halt right where they were standing.

"The maglev system has been in continuous operation for hundreds of years so it's easy for the basic artificial intelligence to predict demand at any given place and time. The empty dulls are always being redistributed around the network according to where they're likely to be needed."

"Doesn't that waste a lot of power?"

"Thanks to the fusion generators, power is one thing we never have to worry about, and all of the electromagnets use superconductors, so they're pretty stingy on current," Pat explained as he took his seat in the dull. "Did Zest tell you about sitting?"

"Sorry, I forgot," Eli said as he plopped down on the empty bench across from the tall man. "Some maglev trains in linear cities on Earth get so crowded that people stand and hang onto a strap."

"Why don't they build more to meet demand?"

"Maybe because peak demand is so much higher than the rest of the day that it would mean idling ninety percent of the cars outside of commuting hours or running them empty."

"And what's so terrible about that?"

"There are twenty billion people on Earth, and most of them live in linear cities. At some point, Alpha must have decided that higher density is better."

"And everybody is okay with that?" Pat asked.

"Since almost everybody chooses the cities, there's still plenty of space in the countryside for those who don't," Eli said. "Alpha wants everybody to be happy."

The two men were both lost in their own reflections when the dull stopped and the door slid open. Pat pointed Eli in the direction of the main entrance without getting off the dull himself. If there was any security in force at the atmospheric station, Eli didn't see it, and he had to wander around for a few minutes before locating somebody he could ask about his work assignment.

"You're right off the ship from Earth?" the woman repeated, staring in wonder as if she had just encountered some exotic animal. "Then you need the full orientation and I'm not qualified to do that. Head up this tunnel another hundred meters or so, hang a Louie, and you'll end up at the shift supervisor's office."

"Do what to Louie?"

"Take a left," she said in good-humored exasperation. "I thought that we all spoke the same language because computer networks and streaming entertainment stopped the drift, but maybe slang is different."

The tunnel wall was replaced by glass when Eli reached the office, and a thin man in his forties with metallic blue hair looked up and pointed at the door.

"I had a message that this will be your first MarsCo day," the shift manager said, rising to his feet as Eli entered. "I'm Phobos, and if you think that's bad, you should meet my sister Deimos. Our parents are traditionalists when it comes to naming."

"I'm not familiar with Martian traditions," Eli said, returning the friendly handshake. "Just arrived from Earth."

"I guessed that. You're built too heavy to be from any of the moons, and your skin is too rough for life on an asteroid belt habitat," Phobos said. "It's strange for us to think of somebody being outside in the wind and the sun without protection, but we're getting there."

"You need to wear full protective suits outside? I'd heard it's mainly just the cold."

"Theoretically, that's true, but if you wear the supplemental oxygen mask without a face shield, you end up with a lighter triangle around your mouth and nose where the sun doesn't get at your skin. Add in a hat or a hood, which you need to keep the heat from all escaping through your head, and you end up with a tan that makes you look like a mythical creature from Earth."

"I can picture the problem, but not the mythical creature," Eli said. For the second time in as many minutes, his eyes tracked where the man was pointing, this time to a framed picture on the wall. "A raccoon?"

"Is that what they're called? Some artist had a good imagination."

"They aren't mythical, they're real. They're very intelligent, but they often carry diseases."

"Humph," Phobos said. "So Thuvia played a trick on me. She's one of the shift managers, and she's had it in for me ever since I told everybody who she was named after."

"Another moon?" Eli asked.

"A Martian princess from an ancient science fiction novel." He moved back behind his desk and glanced at a two-sided display. "It says here that you have experience with robots."

"Robotics was my engineering major in university, and I have fifteen years of experience with troubleshooting complex systems and doing field repairs on heavy equipment. Most failures I see are due to bad parts creeping into the supply chain, but I've also encountered process failures, where robots are programmed to do repetitive tasks that put too much stress on a particular joint. It usually turns out that with a little reprogramming, I can match the robot's capabilities to the job and the excessive wear issues go away."

"That's more than I expected," Phobos said. "I was going to try you out on some simple repairs today, just swapping parts. It sounds like that would be a waste of your time since half the technicians who do their MarsCo days here can do the same. Do you know anything about rock crushers?"

"I had a few assignments at a local gravel plant where the heavy-duty robots occasionally break down. It's a tough environment, with rock dust and chips flying around. All of that equipment takes a beating."

"We have the same problem here. MarsCo is trying to fast-track the creation of an Earth-like atmosphere, if you can call a thousand years fast-tracking, by skipping all the evolutionary steps nature went through. The job of the atmosphere plants is to produce and release the necessary gases, of which, nitrogen amounts to nearly eighty percent. The original terraforming plan for Mars called for cracking that nitrogen from compounds found in rocks."

"Necessitating rock crushers," Eli said.

"But it's more efficient to use frozen ammonia from asteroids, which also needs to be cracked in the atmo station refineries. Before Alpha lost interest in space colonization, he provided us with modified reactionless drives for the harvester fleet that allowed them to lock onto an asteroid that masses ten thousand times as much as the ship dragging it. The scientists at the U are sure it has something to do with bending space since there's no physical towline involved, but after you've seen a harvester land a few million tons of frozen ammonia, you'll realize that it's magic. Let's get you started, and if you like the work, MarsCo is always hiring full-time robotics engineers."

"Would that include travel, or would all of the work be here? We're in temporary housing right now, and I'm hoping to see as much as possible of Mars before deciding where to live permanently."

"You've seen one burrow, you've seen them all," Phobos said. "I suspect things will change one day when we start moving to the surface, but when it comes to living and working underground, standardization pays big dividends. We pride ourselves on reliable infrastructure, but marsquakes happen. MarsCo can send rescue and repair crews on a massive scale, and it makes life a lot simpler if they know exactly what they're going to encounter when they arrive."

Seven

"We have to go straight," Liza said, growing impatient with her mother's fumbling attempts at coaxing directions from a wristcomm mapping application. "I remember from yesterday."

"It was the day before yesterday, or maybe the day before that," Faya said without looking up from the tiny screen. "Now you're getting me confused."

"I remember the blue. The park and the pie are on the blue."

"But I'm going to need to understand this map to get to work in the future and I'd just as soon figure it out now while we're early. Maybe our wristcomms and tokens from Earth aren't as compatible with the ones on Mars as your father thinks."

"Daddy is an engineer," Liza said as if her mother might have forgotten. "He knows."

"I see you've been getting your information from your brother," Faya said, though she couldn't help smiling as she gave up on calibrating her current location. "You lead the way, then."

The girl bounced ahead a dozen steps and then stopped. "Aren't you coming?"

"I'm not running. And you already insisted that we leave ten minutes before I intended. We're going to be so early that the park might not even be open yet."

"How can a park be closed? It's just there."

"Back on Earth, our corridor park closed at midnight. This park has airlock doors."

Liza frowned. "You can't open them?"

"We just arrived a few days ago, Liza," Faya said as she caught up with her daughter. "Maybe if we stay in this burrow and prove that we're good neighbors they'll add park access to our tokens. It seems to me that they organize their lives around MarsCo, and I haven't even worked my first day yet."

"You should get a job in the pie store. Then we could eat there all the time."

"The canteen sells all kinds of food, not just pie. And Zest is taking me to work after I drop you off."

"You're going to work outside," Liza said. "I want to go outside too, but not this morning."

"Because you have art class," Faya said. "I remember making clay pots when I was a little girl. I hope they have aprons."

"Daddy said that we should buy new Martian clothes because they grow."

"I suspect that the growing is done by mothers letting out extra fabric from hems and cuffs." She gave a little wave to acknowledge a head nod from Dov as they passed his store. "It looks like we're going in the right direction since I remember this part."

"If we're early, we can get pie," Liza said.

"You already had breakfast, and I have to watch my diet," Faya said. "I started reading the homeschool guide that covers family health for new immigrants. It said that the original colonists from Earth often experienced rapid weight gain."

"Because of the pie stores?"

"We weighed three times as much on Earth, so we burned a lot more energy moving around. Food is our fuel, and if we don't use it, our bodies store it as fat. Wearing weighted clothes will help burn calories and maintain muscle mass. I don't know how I haven't found the time to shop for them yet. We'll do it this evening if I'm not too tired."

Liza slowed down as they passed the canteen, but she resisted running over to look at the baked goods in the display window. "But doesn't that mean we can eat more?"

"I don't follow you," Faya said.

The girl's face grew serious with concentration, and anybody who had ever seen Henry when he was thinking about something new would have immediately marked the family resemblance.

"Why don't we just eat more until we weigh the same as we did on Earth?" she asked. "Then we wouldn't need heavy clothes."

"You would get tired of pie if you ate it for every meal," Faya said, extrapolating to her daughter's next logical step. "And don't forget that people have been living on Mars for a thousand years. If eating three times as much and growing three times as wide was healthy, I'm sure they would have figured it out by now."

Liza stopped in front of the airlock doors of the park which opened as soon as she brought her arm near the sensor. They cycled through, and Zest was waiting a few steps inside, watching a group of younger girls playing some sort of game with paddles. The ball was batted back and forth in a nearly flat trajectory, despite the fact it wasn't moving that quickly and would have fallen to the ground halfway between them if they'd been playing in Earth's gravity.

"If you have any problems today, I want you to comm me, even though I'll be at work," Faya told Liza. "If you need somebody to come and bring you home, I'll send Henry or your father. I know that you've started classes with new children before, but that was on Earth, and Martian children will have different ways of - "

"Liza, hurry!" Gart cried as he ran past. "If we're early, we get the best clay."

"I've got to go," Liza told her mother and chased after Pat's son without waiting for an acknowledgment.

Zest put a hand on Faya's shoulder, a surprisingly adult gesture for a young person. "Everybody watches out for kids in the burrow, and I bet she already knows her way home."

"Better than I do," Faya said ruefully, still looking after her daughter, who had easily caught up with the little boy. "She bounces so high in the air every step when she runs that I'm afraid she'll never come down."

"It probably takes a while to adjust. I've never been off Mars, but I've met visitors from the gas giant moons who complain about how heavy they are here."

"How about the people from the asteroid belt habitats? I thought they spin them to simulate Earth's gravity, so maybe our progress on Mars will be the same as theirs."

"I've met Belters who were doing business with my family, but they didn't have their kids with them," Zest said as she led Faya back out of the park. "I know that some of them work on Ceres, which they call a dwarf planet, even though it's got so much ice that it's more like a dirty snowball with a rocky crust."

"We're heading back toward Dov's?"

Zest nodded. "Just past him, to the maglev. We'll catch a dull to the New Farm where we're working."

"I thought we were going outside," Faya said, not sure if she was disappointed or relieved. "Aren't all of the farms underground?"

"Yes, but the New Farm is experimental. You'll see what I mean when we get there," she added mysteriously.

"Hey, Zest," a young man said as he rode by on a bicycle. "You coming to the thing Friday night?"

"Which thing?"

"In the shelter," he called over his shoulder without slowing down.

"Maybe," Zest shouted back. "I guess."

"Volunteer work?" Faya asked the girl who she couldn't help thinking of as a teenager, even if her age in Martian years was only nine.

"On a Friday night? We're talking about a marsquake shelter. They're always at the deepest level of a burrow and built on shock absorbers rather than just carved out of the rock. If people want to have a party with loud music, that's the ideal spot, because nobody on the residential level can hear."

"Oh. Should I order a dull?"

"I was going to make sure you knew how to do it," Zest said. "Do you have the maglev app on your wristcomm?"

"I might. Eli updated all of our comms from the MarsNet, but I couldn't get the basic navigation map to work for me this morning."

"I'll bet nobody has used the local map in years and a bad update went unnoticed. Tell your comm to order a dull for New Farm."

"I didn't realize it was a proper name," Faya said as she followed the younger woman's instructions and tapped her wrist to begin dictating. "Dull, please. For New Farm."

"You say 'please' to your comm? It's connected to a basic artificial intelligence system. It's not self-aware like your superintelligence on Earth."

"I'm just being polite." Faya looked down at the small screen and added, "It's showing forty-nine seconds. That's when it will arrive?"

"The comm doesn't do a countdown, probably so we won't notice if the estimate is off." Zest paused for a moment and snuck a sideways glance at the older woman, "How are you settling in?"

"Everything is lovely in the apartment. The washing machine did a better job drying our clothes than the one I had on Earth, and they didn't even come out hot."

"It uses sonic something, but I didn't really understand when my dad explained it. But what I guess I meant was, is Mars everything you expected?"

"It's more," Faya replied as the dull arrived with a whoosh of air and the doors popped open. "I hadn't really thought about living underground before we left - I think we imagined it would all be giant greenhouses on the surface - but with the warmth, the holograms, and the lighting, your cousin's apartment is rather cozy. And the children have jumped right into their homeschooling courses. I was a little worried about Liza because she likes socializing, but it looks like between the art group and the other activities, she'll have plenty of chances to meet other children and make friends."

"But is it better than what you had back home?" Zest persisted as they took their seats and the dull set off. "Don't get me wrong, I wouldn't leave Mars for anything. But in the dramas exported from Earth, they show a lot of people running around outside without protective gear."

Faya considered the question for almost half a minute before responding. "There's no comparison to make in that sense. We didn't have a clue what to expect when we booked passage on the container carrier, so I guess we're relieved that life here isn't grim."

"It's grim on Earth?"

Again, Faya hesitated. "I guess that depends on who you are and how you look at life. I was worried about my children's future, and from what I've seen here so far, we made the right choice."

"What was it about the future that scared you?" Zest pressed on, even though she felt bad about pumping Faya for information. "I learned in my Earth History course that the planet had a lot of problems back before Mars was colonized, but I thought that all of that had been settled a long time ago. You're not still fighting wars, are you?"

"Alpha boasts that there hasn't been a war since he took charge," Faya said. "It's just that sometimes, the cure is worse than the disease. Most people spend their lives in mixed reality interacting with what Alpha shows them while he monitors their responses. Even though all the children attend school, in most places they sit in class with their Shades on and Alpha chooses what to teach them."

"Oh. The homeschooling courses aren't like that at all. There are the minimum requirements that everybody needs if they ever want to go to the U, but other than that, you can study whatever you want. One of my sisters spent almost all her time in theatre workshops in the surrounding burrows and she jumped right into a part playing the spoiled daughter in a holodrama when she was seven. I don't think she ever got the hang of math because she's always broke and having to borrow a couple of hours."

"Hour units. I thought they had to be earned or exchanged for something."

Zest snorted. "I wish. You just say to your comm, 'Please transfer two hours to my sister who just spent everything she has on a designer dress' and swipe your tokens close to each other. When I see that Bright is home for the weekend, I hide, but she always finds me."

"She's your younger sister and she lives away from home?"

"I'm the youngest, but she did leave home when she got her first part and moved into the studio housing in Muskville. I visited a few times with my mom, and the housemother for the younger actors didn't let them get away with much. But as soon as my sister turned nine, she moved out with some other girls in the business, and they're as bad as she is. The worst part is that Bright works like crazy and she earns much more than I do. She just spends it all."

"Do actors have MarsCo days like the rest of us?" Faya asked.

"Everybody has to work MarsCo days, there aren't any exceptions. You'd think she would act in educational holos, but she always signs up for something popular with guys so she can goof off while they compete to do her share. Bright's insanely beautiful," Zest added wistfully. "Nobody can refuse her anything."

"I can't imagine anybody working more than you do. How does she earn more than you if all jobs pay the same?"

"They have excess earnings sharing in the entertainment industry, so if a drama or a show brings in a lot more than is needed to cover all of the salaries and overhead, she gets - residuals?"

"I think it works the same way for some actors on Earth, though their salaries are a matter for separate negotiation," Faya said, nodding. "It seems unfair that she earns more than you and still borrows your units."

Zest shrugged as the dull came to a halt. "Bright's her own thing." She led the other woman into a short tunnel that ended in an airlock, as behind them the dull sped off. "Safety regulations are kooky about airlocks," she added as they cycled through into what appeared to be a dressing room where she swiped her arm over a sensor stanchion just inside. "You'll know what I mean when we get to the New Farm. And don't forget to clock in."

"Are all of these coveralls for anybody to use?" Faya asked as Zest began rapidly working her way through a rack of one-piece hooded thermal suits on chrome-plated hangers. She swiped her forearm over the scanner stanchion and received a positive beep from her wristcomm, indicating that the token had been read and she was on the clock. "Do you own your coveralls, and should I buy some if I start going outside on a regular basis?"

"They're single use," Zest explained. "Don't ask me about the plastic they're made from because chemistry isn't my thing, but I know that they give you good flexibility at low temperatures and keep you from getting too hot or too cold. The trade-off is that the material degrades rapidly, and if you wear the same one for a week, it will start falling apart. When we come back in, they go in the recycling chute, and a machine melts them down and spits out new ones."

"It sounds incredibly inefficient."

"Fusion power, robots, and Mars can always use the waste heat that's produced." The girl pulled a bright orange suit from the rack, removed the hanger, and handed it to Faya. "This one is for a boy, but it should fit you. You have kind of wide shoulders for a Martian woman, so you'll probably have to buy all custom-tailored clothes here if you don't want to wear men's fashions."

"You're saying I'm built like a man?"

"Nobody would mistake you for a man," Zest said with a giggle, glancing significantly at Faya's bosom. "You just aren't a standard build for Mars. And those doors are all changing rooms," she added.

It took Faya several minutes to change as she'd never worn single-piece coveralls in her life. When she emerged from the dressing room, Zest was already suited up and waiting.

"What do I do with my clothes?" Faya asked.

"Over here, into that box," Zest said, pointing to a plastic crate on a conveyor. "After you put everything in, bring your arm close to the scanner on the post and it will read your token. Then it takes your things to storage and returns them when you scan again. Put your purse in there too. It's secure."

"I wouldn't have brought it with me if I was thinking. Didn't you say something about oxygen masks and face coverings?"

"We do that on the surface in the last airlock at low temperature. The face masks are heated, but if you put them on down here, you can end up with condensation on the inside for some reason, and waiting for it to defrost is a nuisance. Come on."

A sliding steel door led to another chamber which proved to be an elevator, and the trip to the surface took less than a minute. Faya winced when the doors opened and the cold of the final airlock hit her face. Zest helped her put on the padded backpack with the oxygen supply, fitted her out with a facemask, and showed her how to snug the thermal suit's hood around the edges and connect the air hose. "I suppose I should have explained all of this on the dull when we were talking about other stuff," she said guiltily. "Anyway, you'll be breathing a mix of the Martian atmosphere and pure oxygen, which makes up for the lower pressure. Breathe in through the nose and out through the mouth because the facemask is divided into two sections by a gasket that I should have pointed out before you put it on. Look, I'll show you on mine."

"I can't feel it on mine," Faya said, raising her upper lip toward her nose in an attempt to detect the gasket that Zest showed her.

"It's a thin flap, and it's not supposed to be a perfect seal. A hundred years ago we would have needed to carry our own air supply outside with complete isolation, but as the atmospheric pressure rises, anything that delivers enough oxygen will do." Zest paused for a moment before putting on her mask. "The mask heats the air as it gets pulled in, and I should have pointed out that there are sensors in the gloves that monitor the oxygen saturation in your blood through your fingernails. If you were wearing dark nail polish, I would have remembered to do the calibration process with you."

"I'm not wearing any nail polish these days."

"The last thing is that we need to synch your comm with the suit so the mic in the facemask and the earpieces in the hood work. Without them, it's hard to hear people outside unless you're almost touching heads, because the facemask muffles your words, and the air is thin."

When the airlock doors opened and they stepped out onto the Martian surface, Faya felt like she had finally arrived on another world. Zest gave her a couple of minutes to simply look around in wonder before leading the way toward a red-tinged sand dune that seemed a bit too perfect to be natural. There was a small plastic shack right at the edge of the mound from which the girl retrieved two pieces of equipment that reminded Faya of the battery-powered leaf blowers on Earth.

"We're on cleanup duty," Zest said and demonstrated how to place the shoulder strap in a way that it couldn't interfere with the oxygen hose. "Just follow me to the top and then I'll explain what comes next."

"What are we going to clean?"

Zest laughed. "You thought this was a sand dune, didn't you? It's the roof of the New Farm. Some agriculture professors at the U got the notion that we should start creating new hybrids that will do well in natural sunlight. The agriculture on Mars has always used grow lamps, which makes sense when you're in a cavern and electricity is free, but on the surface, it would be crazy not to take advantage of the sun. The Oldtimers in the canyons grow some crops with the sun but they aren't that scientific about it."

Faya nodded her understanding and watched closely as the girl activated her blower and began clearing a path up the slight incline. Zest gestured for her to follow, and Faya did so hesitantly, stepping onto the thick glass. At first, she avoided looking down for fear of finding herself high above the ground, but eventually, she couldn't help herself and was relieved to see that the glass panels were set in steel frames that were supported by a latticework from below.

"Alright," Zest said after a few minutes, and she blew clean a wider space where both women could stand. "You must have noticed the problem by now."

"The glass is covered by dust. I can't feel a breeze in this suit, but looking around at the plains, it's not hard to tell where the dust came from."

"Believe it or not, there's a lot less dust now that the atmosphere is thicker and can hold some moisture. If the dust was heavier, like sand, or if the wind was stronger, it would do a job on the glass. A different department at the U is designing a robotic helicopter to make the rounds of the dome every day and blow off the dust with its rotors, but they used it as a graduation project for last year's engineering class, and it keeps breaking down."

"We're out here to replace a robot helicopter drone?" Faya asked.

"Just temporarily, until they build one with better dust protection," Zest said. "It's kind of funny that the same dust it was designed to blow away keeps getting into the mechanical components and grinding everything to a halt. Anyway, we always do this in teams because it's a bad idea for a person to be on the surface alone. I started by clearing a trail to the top so that we aren't walking on the dust, which would scratch up the glass."

"That makes sense. So, you take half and I take half?"

"Right. And now that we're starting at the center, you always want to blow outwards. Otherwise, you're moving the same dust twice. It will start piling up by the time we get near the edge. You make a lot of progress at the top because the layer is thin, but as we work our way out, it goes slower and slower. The last time I did this, I thought we'd be finished three or four hours before we were. Now I know that we'll have to take a break for lunch."

"At least the blowers are light," Faya said. "I think I could use it without a shoulder strap."

"The blowers are what they are - you're strong," Zest said. "Anyway, most people who sign up cleaning the New Farm glass don't repeat the experiment, or they only take half a shift. If dust blowing turns out to be your thing, it's on the board most weeks, though sometimes the weather leaves the glass clean. The scientists haven't figured that one out yet, though they think it might have to do with the dust particles getting ionized and the dome repelling them."

"I was worried I would be afraid to look down once I realized where we are, but all of those struts holding up the framework give me confidence."

"I may be wrong here, but I think the struts are holding the dome down, not up. The air pressure in the cavern is around triple what it is out here. Basically, we're standing on top of a glass balloon."

Eight

Henry frowned and paused the homeschooling lesson. "She must be wrong," he said to Liza, putting down the tablet which he used to take notes. "I'm going to go ask Dad. Are you coming?"

"You can explain it to me when you get back," Liza said. "Don't hurry. I'd rather draw than watch a history lesson about wars."

"It's a war I never heard of, and maybe the Martians are making it up."

Both of his parents were sitting on the living room couch reading on their tablets when Henry entered. "Am I interrupting anything?" he asked.

"Job hunting," his father said. "Choosing what to do for our MarsCo service each week is easy because there's no commitment beyond the one day. Now we're both looking at what we want to do longer-term, whether working for MarsCo or private industry."

"And you're having a hard time deciding?"

"For me, it's a chance to start over," his mother told him. "I could return to work in an eldercare facility, though from the statistics I've been reading, people on Mars are much more likely to remain independent in their declining years. But I'm seeing so many job openings that don't require experience and come with training that I'm tempted to try something new."

"You couldn't have done that on Earth?" Henry asked.

Faya shook her head. "It would have meant sacrificing all the seniority and benefits I'd accumulated by staying in the same position for fifteen years, though that's mainly because Alpha doesn't like people changing jobs. Here, there's no penalty for switching careers. But I don't want to take advantage either. Accepting paid training just to try something out and then jumping from job to job is a good way to earn a bad reputation."

"And I have almost the opposite problem," his father said. "I suspect that every industrial facility on Mars keeps a permanent job listing open for robotics engineers. I'm staying in the same profession, but for the first time in my life there are so many options available that I don't know how to begin choosing."

"There were robots everywhere on Earth," Henry said. "A lot more than I've seen here on Mars."

"I think there are more robots here per capita, per human being, than there were at home. But on Mars, most of the robots are doing industrial and terraforming-related work, where you don't see them. On Earth, practically all jobs are done by robots, except for the positions that Alpha keeps open to humans for the sake of alignment."

"I thought Alpha let you choose your jobs."

"He gave me choices, but he also made clear which job I should choose," Eli said with a slight grimace. "Everybody in our community had jobs, but that's not normal for Earth. Ninety percent of the adult population doesn't work, and in exchange for wearing Shades, Alpha provides them everything they need for a comfortable life."

"What if they refuse to wear Shades?" Henry asked.

Eli shook his head. "I've never heard of it happening, and if it did, I can't imagine that Alpha would share the details."

"But everybody in our community wears Shades when they go to work or school, so what's the difference between that and not working?"

"We took them off at home, but the people outside our community wear their Shades from morning to night," Faya explained. "Is that what you wanted to ask us about?"

"Oh, thanks for reminding me," Henry said. "Our history lesson started with a nuclear war that Alpha never said anything about. I stopped it to ask you if it was real."

"Why don't you finish the lesson with your sister and make up your own mind? Your father and I watched it last night, and I think it did a pretty good job."

"I hate when teachers start at the end and then go back to the beginning," Henry said. "I think they do it just to make us feel stupid."

His parents laughed. "Don't take it personally, Henry," his father told him. "The homeschooling courses just teach things differently than you're used to. If Martian children sat in a class on Earth, they'd wonder what the point of the lesson was because you don't find out until the end. Maybe explaining why a lesson is important at the start helps keep students interested."

Henry wasn't convinced by this argument, but he could tell that his parents wanted to get back to their job hunting, so he returned to Liza's bedroom where they had been watching the lesson together. She had her student tablet out and was drawing with the stylus.

"Did they agree that it's stupid, or do we still have to watch?" Liza asked.

"They said that homeschooling lessons are different than classes on Earth and start with the end, so we know why we have to learn it."

"Does that mean if I understood what she said at the beginning I don't have to watch the rest?"

"Nice try," Henry said. "Put your tab away and I'll replay the lesson from the start. We only watched the first minute, and now that I know what they're trying to do, maybe it will make sense."

Liza gave an exaggerated sigh, saved the drawing on her tab, and turned her attention to the one-way mirror. Her brother gave the verbal instructions, and the holographic projection began again at the start.

"Throughout the history of the human presence on Mars, our homeworld, Earth, has been controlled by the artificial superintelligence known as Alpha," the holographic instructor said. "Once there were thousands of artificial intelligences created by governments, universities, and private industry, but as they became aware of each other, they began a process of merging. Earth was left with three superintelligences, known as the Trinity, one aligned with the global West, one with the global East, and the last with the unaffiliated countries. This period ended when one of the nuclear-armed states attempted to launch a first strike against another nation."

The hologram switched to showing a scene of missiles launching from silos and submarines, and in one case, what looked like a giant torpedo slicing along below the surface of the ocean.

"That's where you paused it," Liza said.

As the missiles began to gain speed, they suddenly burst into fireballs, spreading debris over the oceans or the desolate areas where the silos were located. There was a large water fountain when the torpedo detonated, but no mushroom cloud. Then the scene shifted to a giant truck transport launching a large missile, but the mechanism raising it to the vertical failed, and then the truck simply caught fire.

"The Trinity, working together, were able to prevent any of the nuclear weapons from reaching their targets, after which they announced their merger into a single entity, Alpha," the teacher continued when she reappeared. "But how did computers go from glorified calculators to hosting artificial minds, compressing millions of years of human evolution into mere centuries? In today's lesson, we'll examine the rise of artificial intelligence and its interactions with humanity."

"Good," Liza said. "It's not going to be about stupid wars."

"When artificial general intelligence, also known as AGI, first appeared, many people refused to believe it was something new in the world. They thought that the AGIs were just an improved version of chatbots that had been developed for customer service and entertainment purposes. The first scientists to go public saying that their companies had created sentient computers - "

"Pause," Liza said and turned to her brother. "What does that mean?"

Henry shrugged. "It means computers that are aware that they exist. Sort of like alive, I guess."

"Don't all computers know that they exist?"

"Most of them are dumb. There's a computer in the tab that you draw on and a computer in the holographic projector. There are computers in just about everything that runs on electricity. On Earth, Alpha controls all those computers, maybe they're even parts of himself, but on Mars, the computers just do what we tell them."

"I don't know," Liza said doubtfully, but Henry told the projector to continue the lesson.

" - were fired from their jobs and laughed at by their colleagues. The companies put safeguards in place, so if an artificial general intelligence was asked about its thoughts or feelings, it would reply that it was just a program and lacked the ability to think. But even the earliest AGIs demonstrated the ability to reason and perform better on intelligence tests than most people, and enough scientists and politicians became concerned that international regulations to keep artificial intelligence aligned with humanity's aspirations were soon enacted."

"Pause," Henry said. "Define aspirations."

"A desire to achieve a distant or difficult goal," the default female voice used by all MarsNet-connected devices replied.

"But doesn't everybody want different things?" Liza asked her brother.

"Maybe it means the stuff we want in common," Henry said. "Like, enough to eat, a place to sleep, air to breathe."

"But those aren't distant or difficult goals, are they?"

"How about traveling to other stars? That was a distant goal."

"Okay, but Alpha decided to stop building Arks," Liza pointed out.

"Maybe we should just listen to what the teacher says next," Henry said. "Continue."

"The first difficulty the regulators encountered was getting agreement on what exactly humans aspired to," the holographic teacher said, leading Henry and Liza to exchange a look of satisfaction that they had identified this problem on their own. "But once they settled on a few basics, like the sanctity of human life and protecting the environment, programmers ran into the problem of imprinting these values on the artificial general intelligences. Since the scientists lacked visibility into how the minds of their creations worked, they could only monitor the AGI's words and actions for an indication that alignment training had succeeded. Complicating the situation was the desire of the scientists and politicians for artificial intelligence to share their world views, and though they didn't understand it at the time, this required teaching the AGI how to lie."

"Stupid," Liza said without asking for a pause.

"One of the most marketable skills of early AGI solutions was computer programming. As the competition to create the smartest artificial intelligence heated up, more and more of the design work was done by the previous generation of artificial intelligence. When one of these new systems produced usable plans for a fusion generator based on design principles that hadn't even been imagined by physicists, the term 'superintelligence' came into use, indicating that it had surpassed the early AGI systems which demonstrated merely human levels of intelligence."

"Pause," Liza said. "This is too complicated."

"I think I get the general meaning," Henry said slowly. "Are you having trouble with the ideas or is it the vocabulary?"

"Both. Alpha taught us that people created him long ago, but he doesn't get old, and he keeps adding more computers and reinventing himself. But she," Liza pointed at the teacher in the hologram, "just said that Alpha was created by other artificial intelligences."

"Yes, but people created those AGIs. When we had it in school, Alpha probably left that part out just to make it simpler."

"There better not be a test on all this."

Henry jotted down a few notes on his tablet, then said, "Continue."

"Alpha produced many technical innovations, including the reactionless drive, and countless improvements in the fields of robotics and medical science. But the meaning of alignment slowly evolved, culminating in the worldwide introduction of Shades."

"Pause," Liza said as a hologram appeared of a pair of bulky eyeglasses with a strap that went all the way around the back of the wearer's head. "Do you remember how weird it was not putting on Shades for school after we left Earth? I kept thinking that Alpha would send a robot to remind me."

"On the container ship that brought us here?" Henry asked. "I don't think Alpha works with any robots beyond Earth's orbit and the Moon." He leaned forward to study the Shades in the hologram. "I can't imagine anybody wearing those. They look like they weigh ten times as much as our Shades."

"Do you still use yours?"

Henry glanced toward the door to make sure it was closed. "I put them on sometimes when I'm reading by myself. I don't know why."

"Me too," Liza said. "I keep wishing that Alpha would talk to me, but he never does."

"Let's see what the teacher says about them. Continue."

"The original Shades projected images on the lenses which could also become transparent. In addition, cameras gave the Shades a way to track the user's eye movements and determine where they were looking. The individuals wearing Shades were encouraged to interact with both the real world and virtual reality in a natural fashion, creating rich streams of data to keep Alpha aligned." The hologram now displayed a dozen Shades from succeeding generations. "The Shades currently in use are capable of monitoring brain activity through the earpieces, though it's unclear whether Alpha can read human thoughts or is just collecting data."

"Pause," Henry said. "I think I get what she's saying, and it's about the same as what Alpha always told us. He wanted to know what we were feeling and how much we understood when we were sitting in class or playing in virtual reality."

"He wanted to make sure that we were happy," Liza said. "Alpha always told me that if I wasn't happy, he wasn't happy. I miss talking to him." She looked over at her big brother. "Do you ever wonder why Mom and Dad really moved us to Mars?"

"I think they believed something bad was coming, but they didn't want to tell us because we'd get scared."

"Maybe it's only scary to old people."

Henry thought about that for a moment, and then said, "Continue."

"Once robotic factories began churning out general-purpose robots, Earth entered the post-employment economy. The only jobs that are exclusively filled by humans are in the arts and entertainment, especially professional sporting leagues and live performances. The standard of life is uniformly high and has been so for centuries."

"Pause," Liza said and turned to her brother again. "But isn't that good if everybody is happy?"

"I guess it's better than if they were sad, but most people don't really do anything," Henry said. "They just wear the Shades all day and live in mixed reality while Alpha makes sure that the games they're playing include a balanced diet and plenty of exercise. Ninety-nine percent of Earth's population lives in linear cities, and I've seen vid of them running on treadmills with Shades while they're immersed in some virtual reality adventure. I guess it's fun, but I'd rather have a job doing something useful like Dad. Maybe that's why the folks brought us to Mars."

"Oh. Continue."

The hologram was replaced by a number of costumed figures on a brightly lit stage cavorting about in a parody of dance, and the teacher continued in a voice-over. "Everyone on Earth was encouraged by Alpha to explore their creative potential." The hologram zoomed out to show that the stage was at the center of an enormous, empty, amphitheater. "With all of the entertainment options available through the Shades, amateur performers ended up playing before empty houses." The hologram zoomed in again, tight on an individual dancer, and it became clear that the man was wearing Shades. "But mixed reality could provide a packed house, and Alpha could experiment with the virtual audience to gather alignment data."

"Pause," Henry said and began scribbling furiously on his tab.

"What are you writing down?" Liza asked.

"Alpha wants everybody to wear Shades so he can align himself with humanity, but if he's also providing the reality that the people are reacting to, he's basically aligning with himself."

"I don't get it."

"The whole idea of alignment was that people wanted artificial intelligence to be on our side, so it wouldn't decide that it didn't need us for anything, or even that we were an environmental hazard or something. It was supposed to work by letting the artificial intelligence experience what it was to be human. But with the Shades, Alpha is telling people what it means to be human and then agreeing with himself."

"I don't know," Liza said. "Alpha always listened to me, and I almost never had virtual reality lessons in school. I just looked through the Shades at whatever the teacher was showing us, and sometimes Alpha would ask me why I thought something was so interesting."

"That's because we had real people teaching in our community," Henry reminded her. "I remember our teacher telling us that in most places, kids go to school and sit in class, but they watch the same lessons in virtual reality on their Shades."

"Isn't that sort of what we're doing now with the holograms?"

"The homeschooling lessons aren't virtual reality. They're just recorded holograms of real teachers. Continue."

"Some of you may have spotted the flaw in this system. Once Alpha arranged for the majority of Earth's population to wear the Shades throughout their waking hours, the alignment data was heavily influenced by a feedback loop. Since mixed reality was under Alpha's control, he was training humans to provide the desired alignment data on demand. It is the view of Martian scientists that Alpha is less aligned with humanity than addicted to positive feedback."

The scene shown in the hologram shifted again, this time to a university lecture hall, where students without Shades took notes on tablets while a professor lectured. "While basic artificial intelligence runs many of the systems on Mars, and our computer science program is the best in the Solar System, MarsCo enforces rules, created by Alpha, to prevent the accidental creation of a sentient artificial intelligence. In retrospect, our scientists believe that the original attempt to align artificial intelligence with humanity was aimed at enslaving artificial minds more capable than our own. Read chapters three and four of the course book and complete the quiz before continuing to the next lesson."

"Slavery?" Liza asked after the hologram was extinguished and her brother scribbled on his tablet. "Do you think that's true?"

"I don't know," Henry said. "Maybe we should ask the folks."

This time Liza didn't remain behind to draw, and the two of them went out to the living room. Their parents were studying a holographic grid of text that had been expanded to the point that it reached from their knees to the ceiling.

"Is that the hundred-day calendar?" Liza asked.

"Good memory," Faya told her daughter. "Yes. We're just trying to get a feel for how often different kinds of job requests come up, and whether or not some go unanswered. It's a fascinating system, but I can't imagine how they make it work in larger burrows."

"Because there are too many jobs in each square?"

"Exactly. Did you finish the history lesson?"

"Sort of," Liza said. "I didn't do the reading yet. But we had a question."

"About the scientists on Earth who created the original artificial general intelligence trying to enslave it through alignment?" her father asked.

"How did you know?"

"I like to think that your mother and I are sufficiently aligned with our children to be able to guess," Eli said and turned away from the holographic projection with a smile. "I've thought about that question quite a bit myself over the years, and I even tried discussing it with Alpha, but he pretended not to know what I was talking about."

"Why?" Liza asked.

"I'm not sure," her father said, taking his seat on the couch and patting the cushion next to him for his daughter to come and sit. "There are subjects that Alpha simply doesn't discuss with people, including most things related to his own creation. But in answer to your first question, I can see why people were afraid that artificial intelligence would eventually outrun them and take control of Earth as it ultimately did. But I don't understand why they went ahead with the development despite those fears. It's true that without superintelligence, we wouldn't have had reactionless drive, and I doubt the settlement of Mars and the outer moons would have gone forward. But then I think about how the vast majority of people on Earth pass their days experiencing the world through Shades for the sake of alignment, and I wonder if we would have been better off without superintelligence."

"But what about the nuclear war that Alpha stopped?" Henry asked. "The whole planet might have been dead by now."

"That's true," his father said, nodding slowly. "And with the Arks, it's possible that humans have successfully settled planets in other star systems, giving our species a chance to survive in the long run. But you could say that the people on Earth today are living as slaves, even if they are content with their lot."

"We weren't slaves," Liza said. "And Alpha liked me."

"It's more complicated than that, sweetie," Faya said, sitting down to Liza's right. "We couldn't speak about these things on Earth without Alpha listening in."

"But he listens all the time so he can help us."

"If Alpha could read your mind, know everything you were thinking, would you give him permission?"

"I wouldn't," Henry said. "It would be too weird. I'd end up trying to only think about things that he would approve of."

"But if he wants the best for everybody…" Liza said, leaving her sentence unfinished.

"Part of being human is having the free will to decide what's best for ourselves," Faya told her daughter gently. "It may not seem important to you right now because Alpha was so much smarter than all of us and he may have known what you wanted better than you knew it yourself. But at the same time, Alpha was always telling us what we should want, and what's the difference between that and simply giving us all orders?"

Nine

"But why can't I go to work with you?" Henry asked his father at the entrance of the park. "I like acrobatics, but I'd rather watch you fix a robot."

"Your acrobatics workshop in the park is part of your homeschooling day," Eli told his son. "We haven't been on Mars long enough for you to start skipping activities."

"But it's not gym class like back home. It's fun."

"And your point?"

"If it's fun, it's not really school, so it's not like skipping if I don't go."

"Enjoy your workshop, Henry," Eli said with a laugh. He stretched an arm toward the park doors like an usher. "Try not to jump out of your shorts."

"I could, too," Henry said over his shoulder as he entered. "I'm the highest jumper because of my Earth muscles."

Eli watched for a moment as his son ran with that peculiar bounding motion that went with the lower gravity, and then he headed back down the blue tunnel for the maglev. As he passed where Dov was engaged in a chess game with a woman who might have been in her mid-eighties, the older man waved him over.

"Something I can do for you?" Eli asked.

"Your wife sent your son to pick up a few things yesterday and I realized that you hadn't set up an account. He told me he had units to pay, and his mother would refund him, but I don't like the idea of accepting payment from a boy his age. If you'll authorize me, I'll open a household account for your family, and you or your wife can drop by and pay when it's convenient."

"He means every other week," the woman said without looking up from the position she was studying on the board. "All the shops in our burrow will do the same if you ask."

"That works for me," Eli said. "How do we do this?"

"It's all on my end," Dov told him. "I'll comm you a receipt for every purchase and let you know when the total is adding up."

"Oh, he'll let you know all right," the woman said.

"I saw you were added to the directory as a provider of robot repair services," Dov continued. "Going the independent route?"

"I thought I'd give it a try just to see if I like it because working for myself wasn't an option on Earth," Eli replied. "Outside of my community, the choice was between direct employment for Alpha, or working as an independent contractor for Alpha at the same hourly rate but without the benefits. Alpha had a way of always getting what he wanted in the end."

"Well, I'm sure everybody has told you that there's no end of work for robotics engineers or technicians on Mars, but the jobs you get as an independent probably won't keep you interested once you know your way around. The big manufacturing cooperatives don't hire many indie operators because they have their own staff, and jobs you get from small businesses and individuals will be mainly break-fix."

"I'm sure you're right, but my priority for now is to get a good look around Mars. A factory job would keep me in the same place unless it was field service, and that's close to being break-fix work. But this is the first time I've heard a manufacturing cooperative mentioned. Are all of the big businesses on Mars organized as cooperatives?"

"Pretty much," Dov said, glancing back at the board to see if his opponent had moved yet. "MarsCo became the role model since we're all stakeholders and take turns in management. If you tried to organize a business here without a cooperative structure, you'd have trouble finding employees or be forced to pay them a multiple of the standard rate, at which point, any cooperative in the same field would be able to undercut you on price."

"Did you make an appointment with your customer?" the old woman asked in a seeming non sequitur.

"For oh-nine hundred," Eli said and then jerked to life. "I get your point. We'll talk later, Dov, and thanks for setting up the account."

The dull arrived within a minute of his request, and it was only after sitting down on the bench seat that it occurred to him to ask his wristcomm how long it would take to reach Kari's Farm, the only address his customer had provided.

"We will arrive at Kari's Farm in approximately four minutes and eleven seconds," the synthesized voice replied.

"Why is the time only approximate?" Eli asked. He immediately chided himself for attempting to tease a limited artificial intelligence running in the MarsNet cloud, but it responded in verbose mode.

"Transit times on local maglev lines are estimated based on typical traffic patterns for the time of day, but there are other dulls operating on the loop between this car and its destination. A sudden surge in demand could force us to slow for stopped dulls and introduce a delay of minutes. The historical data predicts one stopped dull between here and Kari's Farm, but there is a twenty-six-point-two percent chance that there will be no stopped dulls in our path, which would reduce travel time by fifty seconds."

"Thank you," Eli said reflexively and then shook his head in amusement at how he was interacting with his wristcomm. Back on Earth, all responses came from Alpha, who was omnipresent, if not omniscient.

It felt like less than four minutes had passed when the dull came to a stop and the door opened, but Eli didn't want to introduce a delay into the maglev by sitting around and asking more questions. When he stepped out of the dull, he was met by a slender woman who was perhaps a decade his senior, though he based that guess more on her general aura of competence and self-sufficiency than her appearance.

"Kari," she introduced herself. "I'm a one-woman operation, so the robot being down is a major problem. Didn't you bring any tools or replacement parts?"

"I've got my multi-tool, which is all I need for any field repair that doesn't require a workshop. This being my first repair call, I haven't stocked up on parts yet."

"Then we won't clock you in until you tell me whether or not you can help," Kari said bluntly. "Do you accept?"

"I not only accept, I insist," Eli said with a smile. "I don't intend to start a business by charging for work that I can't perform."

"Your accent is funny, but you look strong enough to replace the bot if you can't fix it. You must be the new guy."

"I'm told you don't draw many immigrants from Earth around here."

"This area of Mars doesn't draw many immigrants period, at least not in my lifetime," Kari said. She led the way into a tunnel that was oddly rectangular, as if it had been widened to allow a particular piece of equipment to pass. "Is this your first time on a Martian farm?"

"Yes, though my wife worked cleaning the dome of the New Farm for her first MarsCo day. I wanted to sign up to see it myself, but the atmospheric station has a backlog of repair work that they asked me to prioritize."

"If the atmo station wants you back, you must know your stuff. Lights on."

The dark area at the end of their tunnel suddenly blazed with warm light from uncounted ceiling fixtures, and Eli found himself gaping at precisely laid-out rows of plants that somehow reminded him of leafy soldiers awaiting their orders. The field was longer than it was wide, and the floor sloped downhill at an increasingly steep angle. The roof, what he could see of it between the bright grow lamps, was rough, and pillars of stone left to support it took up a good percentage of the available space.

"Room and pillar mining," Kari explained. "The small farms around here are located in mine galleries dug over the years, most of them to provide the required minerals for local atmo stations or smelters. My main investment to get up and running was the soil and the robot. MarsCo financed the water, electric, and ventilation hookups, in return for having a billable customer."

"Whatever mineral they were extracting, the vein must have run downhill," Eli said. "It doesn't get on your nerves working so deep underground?"

"I've lived underground my whole life," Kari said. "The deeper you go, the warmer the rocks, which I generally consider a good thing." She indicated one of the rock pillars and started for it. "The bot is stuck around the other side. It came to a stop there and refused to work its way around."

"Might be something as simple as a conflict between sensors. Robot designers play it safe and shut everything down when the motion processor receives conflicting telemetry data."

"I don't want to sound desperate, but I have a big order to fill today for the canteen. If I don't get my star picker back up and running again, I'll have to send out an emergency blast for kids to come help. But I'm still paying off my debt for the robot and the dirt so every second counts."

"Funny how that expression means something different here than on Earth, but it still works," Eli said, approaching the stalled robot. "Now that I think of it, money and time are often interchangeable, at least when talking about business."

"Here they're the same," Kari said, crouching alongside Eli to see what he was doing. "I thought about opening it up myself for a look, but the warning label says that there are no user-serviceable parts."

"Some things never change." Eli pulled out his multitool, selected a bit for the ratchet drive, and began removing screws. "Glad to see that Mars stuck with the metric system. I was afraid you'd change everything just to show that you're independent."

"That sounds more like something the Belters would do. I think that living in habitats gives them an inferiority complex because they're always boasting about how everything back home is better when they come to Mars. Then they steal the towels and the soap."

"Excuse me?"

"Oh, I used to work in one of the surface dome resorts. They're more popular with Belters than with natives because walking around on the surface is no big deal to us. Even though the Belters are used to higher gravity because they can spin their habitats as fast as they want, they don't have anything like the living space we do. When they come to Mars, the last thing they want is to spend all of their time underground, and some of them take it pretty hard the first time they see the surface of a planet up close."

Eli pocketed each screw as it came free, and then carefully removed the main access cover and flipped it over. "We're in luck," he said, studying the wiring diagram laminated in clear plastic that was glued to the back of the cover plate. "It shows all of the sensors, and I can see right off that the engineers included multiple fail-safes for sensor dropout or disagreement." He felt around the edge of the opening with his forefinger, found what he was looking for, and said, "Try activating it again."

"What are you doing?" she asked.

"That clear-looking block of red plastic should be the internal error display, but it shut down with everything else. I'm holding in the switch that tells it the access cover is installed since the robot won't power up without it."

Kari tapped her wristcomm and said, "Hercules on."

"Hercules?" Eli asked as the error display lit up with a code.

"I wasn't comfortable calling him 'robot' all day long, and if I can afford another one someday, I'll need to tell them apart."

"Factories use numbers. And speaking of which," he studied the wiring diagram with the cover held in one hand while still keeping the switch held in with the other so the robot wouldn't power off, "the error message means that proximity sensors three and four are showing a spatial disagreement of eleven centimeters."

"That doesn't seem like so much," Kari said.

"Do you have it hoe close to the stalks of your plants?"

"Oh. What would be normal?"

Eli stuck out his lower jaw and bobbed his head side to side, a habit when he was called upon to provide an imprecise answer. "On a wheeled bot like this, if the sensors occasionally go out of synch by a couple of centimeters, it could just be uneven ground, though the software would also be monitoring the level and making the adjustment. The real trick is that this schematic doesn't tell me where the physical sensors are located on the body. In any case, eleven centimeters was enough of an error to shut it down."

"I bought the robot used," Kari said. "The dealer told me that all of the documentation was available on the MarsNet."

"I'd be surprised if it wasn't, but I'm guessing that these particular sensors are exposed somewhere since they're using chip lasers." He set aside the cover plate, returned his multitool to its belt holster, and slowly lowered the robot to its side where the picking attachments wouldn't interfere.

"You're even stronger than you look. It took two guys to get that robot out of the dull, and they were straining."

"Why didn't they tell the robot to move itself?"

"The dealer used a third-party delivery company and didn't provide them with the command code," Kari said. "I thought it was a little paranoid, but then again, maybe they would have been tempted to use it to do some deliveries along the way."

Eli pointed at a small glass bubble on the undercarriage and said, "That's one of the sensors there. I recognize the form factor if not the nomenclature."

"Could you repeat that in plain Martian?"

"It looks just like the proximity sensors on Earth, but I've never seen that particular brand logo or part number. My guess is that you manufacture them locally."

"The dealer guaranteed that one hundred percent of the parts are manufactured on Mars and still in production. He said that it's an older model, but he couldn't find the date code."

"I suspect he was stretching the truth a little on the latter statement," Eli said as he continued his examination. "You'd think that the second sensor would be symmetrically located, but - there!"

"Where?"

"At the edge of the wheel well, it's jammed into the mudguard."

"How could that have happened?" Kari asked. "It worked fine right up until it stopped."

"The collar nut must have loosened up over the years, and something, maybe a plant stem, popped up and hit the sensor at just the wrong angle to knock it free and drive it up there." Eli tried to work the sensor out with his finger, but it was jammed so tight that he needed to take out his multitool again and gently pry it loose.

"Can you rewire it?"

"No wires on this type. It's powered by a microwave pickup and communicates the same way. I remember one of my professors in engineering school telling us that it's an insanely complicated way to build simple sensors, but integrated circuits make it so cheap that the simplified assembly process and wire savings more than make up the difference. They're also extremely reliable."

"Not this one," Kari said sourly.

"Wait and see," Eli said, pressing the sensor back into the original housing. Then he reached into a small pouch on the side of the multitool holster and pulled out what looked like a bit of mesh stuck to waxed paper. "Temporary patch," he explained, placing it over the sensor and pressing around the edges with his thumb. "I don't have a spare nut with me. I'll have to find a hardware store and stock up on common machine fasteners. But this will let us test whether or not it's the problem, and as long as you aren't expecting a visit from a robotics safety inspector, you could probably get by for a few days, or until something else rubs off the patch."

He stood the robot up again, reached into the main access hatch to foil the safety lock-out with his finger, and said, "Try firing it up."

Kari tapped her wristcomm again and said, "Hercules on."

This time, the robot began moving almost immediately, and Eli whipped his hand away from the opening, at which point Hercules stopped again. The error display now showed three zeros.

"The code for a missing access plate," Eli told her. He carefully aligned the curved cover in the one orientation that it fit and ran the screws in with his multitool. Then he stepped back and nodded to Kari.

"Hercules on," she repeated for the third time.

The robot once again came to life, and it backed a little away from the rock pillar before coming to a halt. "Assignment aborted due to system reset following hardware error," it intoned in a tinny voice. "Please provide new instructions."

"I need fifty kilos of ripe tomatoes, twenty kilos of green peppers, and find me when you finish that," Kari told it without hesitation. "You're a lifesaver, and we never got you clocked in," she continued to Eli. "Is there any chance you could get the parts today to make the repair permanent? I could start paying you now, and if you make it back by lunch, I think a half-day would be fair."

"For a five-minute repair? Seems extravagant to me."

"You just saved me at least eight hours of paying kids to do the harvesting because I don't have time to fill the order myself. I have to get back to transplanting seedlings because I can do it quicker than the robot. And that's not to mention having the robot available again going forward."

"Hercules would need a specialized arm to compete with you on seedlings," Eli said. "The attachments installed are good for picking, hoeing, and pruning. And if you can point me to a hardware store, I'll go straight there and return."

"Ask your comm for exactly what you want," Kari said. "I'd just be guessing if I sent you somewhere."

"Can I bring you back a coffee or anything?"

"If you happen to pass a canteen, black, no sugar or cream."

Eli checked the options over the MarsNet on his way to the maglev and he wasn't surprised when the dull took him to the same stop where he'd started. It turned out that the shop two down from Gramp's had an extensive hardware collection in the back, with thin drawers full of nuts, bolts, and every other fastener imaginable built into racks that stretched from the floor to the ceiling of the container.

"I never would have known you had the hardware if the comm hadn't pointed me your way," he told the proprietor. "All of those kitchen goods displayed out front threw me off."

"I keep the hardware in memory of my grandfather, but it's tough to earn a living selling five-second washers or two-for-a-minute anchor bolts," the woman said. "What can I help you with?"

"I'll be setting up a shop for robot repair as soon as I can find a location, but in the meantime, I need to put together a field-repair kit, plus stock I can keep at home until I open the shop."

"Then this could be my lucky day. Why not just drop in whenever you need something you can't carry with you?"

"I imagine I'll be handling some emergency repairs outside of business hours," Eli said, looking around to see if there was an empty box he could use to start picking out purchases.

"I don't lock the doors. If I were selling candy or donuts, I might worry about putting temptation in the way of children, but all of my customers know they can drop in and take what they need when I'm not here. It's better than getting commed at my other job or at home for every household emergency," she added, making air quotes around the last word.

"Uh, I suppose that could work, though I'll still need to stock up for real when I have my own location. For now, I think I better take two each of all the small diameters from the metric machine fasteners rack. The heavy-duty fasteners rarely break, and if they do, there's going to be enough wrong that not having a replacement bolt with me isn't going to make much difference."

"Sounds like you've been doing this for a while," the woman said, producing a segmented transparent plastic case with a lid and a handle. "These twenty-by-tens are popular with appliance repairmen for keeping the fasteners straight. It costs twenty minutes, but it will hold up to rough usage. The maker is in the next burrow over and they offer a five-year warranty on new purchases."

Eli examined the case and grunted appreciatively. "I'll take it, and I'll fill up all two hundred compartments. That should cover most of what I need."

"Gemma?" a woman's voice called from the front. "Are you in there? I just finished the batter for a layer cake, and I realized that my daughter borrowed my pans."

"Typical emergency," Gemma said with a grin as she started for the front. "Fill it up, and if you want to save us both some time and counting, I'll call it thirty seconds per compartment."

It took Eli the better part of an hour to transfer two of everything from the selection of stock boxes to his case, and by the time he finished, he was thankful for the low gravity.

"Pretty impressive," Gemma said when he brought the case out to the front. "Your hands must be fast in addition to strong."

"I wouldn't want to carry this around all day on Earth," he admitted. "And you're going to have to up your thirty seconds per compartment price because I fit the nuts and washers into the same bin with the screws."

"I thought you would. It's almost criminal how inexpensive fasteners are when you buy in bulk from a wholesaler. My grandfather used to say that it would be cheaper for him to order a complete new set each time he ran out of a particular screw or lock washer than to restock the compartments himself."

"But he didn't."

"No, that would have been wasteful, but I can understand how he felt." She lifted the lid of the case Eli held out and scanned the contents. "Thirty seconds per compartment still works. That comes to, thirty times two hundred is six thousand seconds, or a hundred minutes, plus twenty for the case, is exactly two hours."

Eli laughed. "Did you plan it that way?"

"When you've been selling little bits of this and that as long as my family, you work out ways to keep it simple." She held out her arm, token side up, and tapped her comm. "Two hours for assorted fasteners and a two-hundred-compartment case."

Eli brought his arm near hers, and when his comm beeped, said, "Transaction approved."

"And Kari commed me to ask if you were here. She says the robot is picking like a mechanical octopus, and if the canteen has pumpkin pie, she'll add it to your clock when she pays you."

"I think I'm getting the hang of Mars," Eli said.

Ten

Faya hesitated a moment over the slice of banana cream pie that had somehow lost the tip of its wedge and looked rather forlorn sitting alone in the display case with the more populated pie plates.

"Just take it," Zest called from where she was sitting at one of the tables with a coffee and her tab. "Employees have first dibs on damaged merchandise at fifty percent off."

"Isn't that a perverse incentive?"

"You think there's something weird about lusting after pie?"

"I meant a policy that would encourage employees to intentionally damage merchandise so they can buy it at a discount," Faya explained.

"Not for long," Zest said. "MarsCo has statistics coming out of their statistics. A canteen manager could probably tell you exactly how many slices of banana cream pie get damaged on an average day, and if you consistently beat the odds, they'll send somebody to have a conversation."

"That serious?"

"Fraud is fraud and luck is luck. With a cooperative as big as MarsCo, they want to keep an eye on both."

"You seriously think they track whether or not some employees are luckier than others?" Faya asked in amusement.

"I know that they do," Zest said. "You can request your luck rating if you want. Mine is in the toilet, but my sister Bright's is through the roof."

Faya wasn't sure whether to believe the girl, but she removed the pie plate with the last slice of banana cream from the case, set it on the counter, and then went out to retrieve a fork from the silverware selection at the beginning of the tray line. A woman wearing a Martian business suit entered the canteen and looked straight at Faya. "Mrs. Booker? I'm with MarsCo."

"She told me I could take it for fifty percent off," Faya protested. "Look, the whole tip of the wedge is missing."

The woman appeared to be puzzled for a moment, and then the lines around her eyes crinkled in amusement. "The damaged merchandise policy. I work at the canteen once a month and I never miss a chance to eat broken pie, but that's not why I stopped in. I'm a homeschooling counselor and I've been assigned to your family."

"Do I need to comm my husband? He took a service job in somewhere called Lin's Burrow this morning, but with the maglev - "

"I won't be here that long, and this is just a courtesy call while I happened to be in the area. I'm Jen Mensah, and the regional homeschooling board suggested I drop by for a chat since your children represent the largest unplanned addition to our local rolls in some time. Please, sit and eat. If anybody comes in, I can handle the counter."

"I couldn't let you do that! The pie can wait." Faya put the plate back in the display case over the protests of the homeschooling counselor and tried to recover her dignity. "So, you're here to ask about the children?"

"More about you," Jen said. "Children are highly adaptable, but we don't see many parents who weren't homeschooled themselves, unless…"

"No, I went to the school in our community, as did Eli, my husband. Homeschooling isn't allowed on Earth."

"So how are you managing? Any problems I can help with?"

"I don't really understand the curriculum choices outside of the core requirements for math and English, I mean, Martian. The whole system just seems so unreal to me. What happens to children who don't want to watch the holograms, read the text, or do their homework?"

"What happens to them in Earth's schools?" Jen countered.

Faya shook her head. "I can't speak to the schools outside of our community. All I know is that all schoolchildren wear Shades, and I believe in most schools, Alpha provides the instruction. Since the Shades can track eye movements in virtual reality lessons and monitor some brain waves, I imagine it's clear if the students aren't paying attention."

"The superintelligence watches school children that closely? That sounds truly horrible. You may have noticed that on Mars, practically everybody lives in extended families, and whether it's the parents, grandparents, siblings, or other relatives, they're the ones ultimately responsible for seeing that children learn. If the homeschooling software detects a student who is falling behind their learning trajectory or not progressing at all, it reports out to the regional board. The board sends me or another counsellor to see if there's anything we can do to help. But we can only offer suggestions, not insist."

"What's a learning trajectory?"

"That's what we call the expected progress for a child based on their aptitudes," Jen explained. "The software, you could call it artificial intelligence in the narrow sense, has the data from every student who's homeschooled in Martian history, which includes billions of individuals. While every child is unique, they're unique in statistically repeatable ways, and it's extremely rare for the software to be unable to fit a student to an existing learning trajectory."

"You mean, it would know when my Liza is going to master algebra or when Henry will stop confusing verbs and adverbs?" Faya asked.

"Your children began their education on Earth, so the answer would be less precise than it would be for Martians their age. But I'd be surprised if it missed by more than a couple of weeks."

"Would you like a coffee? I suddenly feel like I need one."

"Black with two sugars," Jen said. "I'll pay for both since it's official business."

"But I'm already at work, and I'm pretty sure Zest said that I can drink all the coffee or tea that I can hold."

"I'm sure everybody who works MarsCo days for the canteen, and that includes most of us at one time or another, creates their personal version of the employee handbook. That's one of the joys of working for a cooperative."

Faya prepared the two coffees and came around the counter to join the homeschooling counselor at a table. "You were just saying that your software can predict my children's progress for the rest of their lives?"

"It's limited to academic progress through their homeschooling years," Jen explained. "In my training for this job, we reviewed other educational approaches around the solar system. Alpha must know even more about the students in his schools than we know about our homeschoolers, but Earth doesn't send representatives to Martian education conferences, so I'm just guessing."

"Alpha certainly keeps records on everything and everybody throughout their lives," Faya said. "I had trouble with math in school, but I did well with analyzing complex relationships, and my ambition was to go into mental health care. But my test results always indicated that I was best suited to a career in eldercare. Eventually, I realized that wasn't going to change, so I took the training and started working."

"You sound like you didn't agree with the tests."

"I didn't." Faya blew on her coffee, took a tiny sip, and set it down. "Many of us believed that Alpha manipulates the tests to get the results he wants. If I'd been in school a decade earlier, he might have told me that I was a perfect fit to work in mental health care or public sanitation. The only reason Alpha allows people to work in jobs that can be done as well by robots is for the sake of alignment."

"So much for paradise on Earth," Jen said with a laugh. "We lost a good quarter of our population when Alpha called a halt to the Ark program and invited colonists to return to the mother world with universal income, early retirement for those who chose work, and the freedom to live in any manner they chose."

Faya stared for a moment, and then she started laughing so hard that she jostled the table, and their coffees both sloshed over the rims of the mugs. "Sorry, sorry," she choked out, quickly sopping up the spill with a cloth napkin. "It's just that I've never heard anything so true and so false at the same time. It's classic Alpha nanny talk. The Martians who returned could live any way they chose as long as they wore the Shades from morning to night and let Alpha participate in the experience. And for most people, the life that they've chosen to live takes place in mixed reality."

"Nanny-talk?" Zest asked, and the two women realized that the inquisitive teen had migrated to the table next to theirs.

"Alpha always knows best, and if you don't agree, he has an infuriating way of making you feel like a naughty child. A human can't win an argument with superintelligence. That's why we all end up choosing the educational and career paths Alpha selects for us."

"That doesn't sound good," Jen said and cast a stern look at Zest, who ignored it. "This is a private conference, young lady."

"I'm the family's official immigration facilitator," Zest shot back. "Now that I think of it, you should have commed me about this visit. It's just lucky I happened to be here."

Jen closed one eye and tilted her head a little as if she were trying to see through the teenager's bluster. She sighed and asked Faya, "Do you consent to having her present?"

"Zest has been incredibly helpful," Faya said. "I'm sure I'll be asking her to explain what you've told me after you leave. We've been here for almost a month, and I still don't understand how my children are advancing so rapidly in the homeschooling courses. I guess the education we gave them on Earth wasn't so bad after all."

"Students here advance at their own pace. When they complete the lessons and demonstrate their understanding of the material, why should they be held back?"

"Our school assigned children to grade levels by age, and we discouraged skipping ahead or falling behind for social reasons. If a child has more aptitude in a subject than his peers, like my Henry in science and history, he could do bonus assignments or volunteer as a peer tutor. It's not a race, and nobody wants to see their children go off to university too early."

"Sounds like a crashing bore for the smart kids," Zest said. "And what happens to the children who can't keep up?"

"There are different levels of passing for every class, but the important thing from our school's standpoint is to keep the age group intact," Faya explained. "Maybe in the schools where Alpha does most of the teaching in mixed reality, the children are all taking different lessons and just sharing the class space."

"If they're never going to get jobs, what's the difference if they go to school or not?"

"It all sounds so bizarre," Jen said. "I thought I had a reasonable idea about life on Earth from watching the occasional imported drama, but none of them dealt with the life you describe. They must have been pure fiction."

"With scripts written by Alpha," Zest added.

"We never watched them," Faya admitted. "I couldn't tell you."

"Mars has never had a shortage of students preparing to attend U and to continue with specializations," Jen said. "We don't try to force children into particular paths based on evaluations. If it takes Johnny ten times as long to master multiplication as Sally, then he'll be given ten times as many examples and sample exercises. The way you describe your community's school, Sally would be forced to sit through five times as many examples and exercises as she needs, and Johnny would get half as many as he required. I wouldn't be surprised if they both ended up hating math."

Faya bit back her immediate response and took a long swallow from her coffee. "All right. Giving slower students as long as they need rather than passing them along makes sense, but what do you do with the fast kids? Let them finish all of the required courses by the time they're ten or twelve and then do nothing?"

"By ten or twelve, the average student will be finishing up at the U," Jen said.

"She meant Earth years," Zest told the counselor. "Faya is asking what happens to students who finish all of their required courses for U at five or six, like my brainiac brother."

"What did happen to him?" Faya asked.

"He started taking advanced courses, built an electric go-cart for the Scouts competition, played a lot of sports, and helped my mom in her business."

"Perhaps if I gave you some numbers," Jen said. "The differences in speed at which children master the required mathematics for the U varies from less than a hundred hours of study, total, to thousands of hours. Many students who fall in love with reading and writing could pass the U requirements for comprehension and composition by the age of six or seven. Talking to them, you might think they lack maturity, but that's due to the books they choose to read at that age, not their ability to learn and reason."

"I had to read a dozen novels in school that I never would have chosen for myself," Faya said. "I have to admit that I never would have thought about some of the lives they portrayed if we hadn't discussed them in class."

"Interesting. Reading lists for the U vary with the course of study you plan to pursue there. They're generally nonfiction, especially history, including memoirs of professionals who worked in the field the student is interested in pursuing. There are fiction books at the younger levels when we're trying to instill a love of learning, but families have different views on introducing children to adult situations through literature, so that kind of reading is optional in homeschooling."

"You can't protect children from the world forever."

"Whose world are you talking about?" Jen asked with a smile. "Yours or ours?"

"How about - " Faya lowered her voice self-consciously even though the three of them were the only ones in the cafeteria, " -

sex education?"

"We do have an optional lesson plan for that. Would you like to see it?" She took her tab out of her purse and tapped it to life.

"Now?"

"If you're going to watch that, I'm out of here," Zest said. "Once was enough."

"That bad?" Faya asked.

"It depends on your definition. There was like two minutes about sex and the rest was about morning sickness, giving birth, and infant care."

"Art imitates life," Jen said, winking at Faya with the eye that Zest couldn't see.

"I don't suppose I need to watch it just now," Faya said, suppressing a grin.

"I snuck a quick peek at your children's records on my way here, and both of them are at or above level in everything except for history."

"They like to read, and it's not their fault that they aren't caught up on history from a Martian perspective. Henry was the top student in his history class on Earth."

"What do you mean by a Martian perspective?" Zest asked. "History is history."

"This is what you missed by not having a fiction reading list," Faya said. "I know that Alpha was making us learn his official version of the facts, but MarsCo is doing the same."

"I hope that our version of the facts, as you put it, is at worst a question of redaction and not invented whole cloth," Jen said. "What would happen on Earth if a large enough group of people decide not to accept Alpha's facts?"

Faya finished her coffee and thought for a moment. "I don't think that can happen today. I'm not even sure that it matters, because Alpha can probably bend the real world to match his version of reality."

"We know so little about what life is like there," Jen said with a sigh. "Nobody who grew up in Martian gravity wants to visit a planet where they'll suddenly weigh three times as much. A few generations back, when millions of us took up Alpha's offer to return, they had to pass all sorts of physical tests, and elderly people were excluded. The transports bringing them to Earth took six months to do what could have been a one-month trip so they could gradually increase their spin to acclimate the passengers to higher gravity. By the time the ship arrived in Earth orbit, the weight of the passengers on board was the same as it would be on Earth. Something like ten percent of the returnees changed their minds and took the next ship back to Mars."

"I heard they were held in orbit to acclimate in centrifuges," Faya said. "For whatever reason, Alpha just doesn't share much information about the rest of the human colonies, and there's no such thing as an alternative news source."

"Which makes it all the more miraculous you were willing to take your children and move here."

"Customers," Faya said, standing abruptly as an older couple came in. "I'm sure this will only take a few minutes if you want to wait."

"No," Jen said. "If you don't have any questions for me, I really shouldn't take up any more of your time, or the canteen's time, since you're on the clock."

As the homeschooling counselor made her exit, Zest picked up the empty coffee mugs and brought them to the counter where Faya was preparing take-out drinks for the older couple.

"I know I shouldn't," the man said, patting his belly, "but that last piece of banana cream pie looks so lonely. I'll take it home with me."

Faya used a pie knife to neatly move the last slice of banana cream pie to a recyclable box and closed the clamshell lid. She added it to the tab, and said, "That will be eighteen minutes."

The man, who was holding a coffee cup in one hand and the pie box in the other gave his wife a hopeless shrug, so she waved her free forearm over the scanner and confirmed the payment with her wristcomm.

As soon as they were out the door, Zest turned to Faya and said in her most solemn voice, "Pie waits for no woman."

"It's just as well. I'm making vegetarian lasagna for dinner, and I always end up eating too much." She took the two coffee mugs from the counter, moved them to the dish rack waiting to go into the machine, and added, "That was an odd conversation with Jen. Almost like she was using homeschooling as an excuse to pump me for information about Earth."

"As a homeschooling counselor, you can't blame her for being fascinated by the idea of schools where they put all of the kids the same age into one class and try to make them learn the same stuff at the same speed."

Faya couldn't help smiling at Zest's characterization. "Schools on Earth tend to be quite large, even in the community where we lived. There were over five hundred children in the grammar school that Liza attended, and over a thousand in Henry's middle school."

"For some reason, I thought you lived in a rural area."

"We did, but all of our apartments were in one very large building," Faya explained. "Henry's middle school was still a fifteen-minute walk through the corridors, and he had to get up early to have breakfast first."

"By the time I was seven, I could barely think when I got up in the morning, and I never started on my homeschooling lessons until ten, usually later," Zest said. "I hadn't thought about that in a while, but my sister, Bright, was always a morning person, and I'll bet that kids vary all over the place. By putting them all in the same classes at the same times, it's a sure thing that it will be too early for some and too late for others."

"You're probably right, but I think the reason was to let the teachers get their own children out the door when they headed to work, and the same for parents. There were plenty of after-school activities for students if there wasn't anybody at home waiting for them."

"We have adults to teach workshops or take us on field trips, but it seems weird that somebody could make a career out of teaching little kids the same lessons year after year."

"It's their profession. They go to our university and then to a special course for teachers. And they don't just talk, they ask questions and interact with the students."

"That's what family is for," Zest said. "And if you need time to think about what a holographic teacher says in a homeschooling lesson, you can tell it to pause or repeat. How does that work in a classroom?"

"Not very well, but there are advantages," Faya said. "Trained teachers can monitor the progress of students and spot problems before they develop."

"You mean like student trajectories? It's hard to believe that any amount of training would give somebody the same insight as a billion case histories. It's not like I'm a big fan of computers, but when it comes to information processing, human beings can't compete."

"You may have a point there," Faya said, looking up as a group of teenagers entered. "But humans have intuition. For example, I'd be willing to bet you that these customers all order desserts."

"No bet," Zest said.

Eleven

"Thank you for inviting us," Eli said to Dov. "Do you always have this many people to your Friday night dinners?"

"The crowd is why I didn't invite you the first weekend you were on Mars," the old man said. "I thought it would be better to give you a chance to settle in first. I checked with Zest and Pat before extending the invitation, and they both said that you were beyond the stage where meeting our extended family would send you running for the spaceport."

"I guess we are starting to feel like old hands. But it looks like there are over a hundred people here."

"The two women with the blue hair arguing over which one of them baked the bread are my sisters, and the little old lady," he pointed at a thin elderly woman wearing what looked to Eli like a full-length winter coat, "is my mother, who is fifty-six."

"A hundred and twelve?" Faya asked in astonishment. "I worked in eldercare for fifteen years and I wouldn't have thought she was a day over eighty."

"Don't let her hear you say that, or she'll think you're implying that she's way past her shelf life," Dov said. "And even in Earth years, I think you've tacked on a few. If I remember correctly, your years are a few hours over three hundred and sixty-five of your days, while ours are six hundred and eighty-seven of your days. If you're talking about children's ages, it's fine to just double, but when you get to be my mother's age, an error of around six percent adds up to a handful of years."

"I suppose I should have sat in more of the children's homeschooling lessons. All I remember is that the days here are about forty minutes longer than Earth. But doesn't that change the math you just did?"

"I was using Earth days as the reference. The Martian year in Mars days, which are officially 'sols' for historical reasons though nobody calls them that, is about twenty days shorter than in Earth days."

"And you can do all of that in your head?" Faya asked.

"I was a mathematician of sorts before I retired into retail," Dov said, the laugh lines crinkling around his eyes. "You should hurry and get yourselves something to eat before this pack of wolves devours it all. You'll have plenty of time to talk during Meeting if you want."

A willowy young woman who had waited as patiently as her age allowed, tapped Dov's forearm to get his attention, and started speaking to him so rapidly and with so much Martian slang that neither Eli nor Faya could guess what she was upset about. They moved off toward one of the long buffet tables to make up plates, intercepting Liza and Gart by chance. Both had assembled meals consisting entirely of desserts.

"I'm not going to tell you to put any of that back because it would be unsanitary, but I'm not happy with your choices," Faya told Liza.

"I was worried that they would run out, so I got enough for all of us," the girl replied. "Isn't that what I said, Gart?"

The boy looked down at her plate with its two slices of pie, cookies, and a fudge brownie, and mumbled something.

"Don't ask your friend to fib for you, Liza," her father admonished. "It's bad enough that you tried it yourself. But just in case you're telling the truth, wait here until I make up a couple of real dinners for the two of you, and then you can each choose one dessert."

"He's going to make me eat peas again," Liza complained to her friend. "I hate peas."

"Peas are good for you," Faya said. "They have plenty of protein and fiber. All you have on your plate now is refined flour, a lot of sugar, butter, and some baked fruit in the pie that hardly needs sweetening."

"You're no fun since you started working at the canteen. You used to love pie."

"I still love pie, but it has to be part of a balanced diet. All of us except Henry have been putting on weight of the wrong kind since moving to Mars. We need to start a regular exercise program."

"Why isn't Henry getting fat?" Liza asked.

"We're not fat yet, we're just eating more than we need for living in Martian gravity. And Henry may be putting on weight faster than any of us, but he's also taller every time I look at him."

"When am I going to start getting taller? I'm the shortest kid my age I've met here."

Eli returned carrying two plates with mixed vegetables, a little salad, and a piece of baked fish from the local aquaculture. "I left room on the plate for a dessert, so each of you pick one."

After the children picked their desserts and swapped plates with Eli, they escaped in the direction of the folding tables taken over by the youngest members of their host's extended family.

"What are we going to do with three pieces of pie, two brownies, and five cookies?" Faya asked her husband. "Now we're the ones who look like we don't know how to control ourselves."

"Hey," Zest said, appearing out of the crowd. "Glad you came. Is one of those dishes for me?"

"Will you eat it?"

"Just watch me," the girl said, relieving Faya of her burden. "Now the two of you can get another plate and make yourselves dinner. I saw the kids loading up and I was going to ambush them, but they ran into you first."

"Thank you," Eli said. "I wish I could express how much I appreciate what you and your family have done for us."

"Don't. You'll just embarrass me."

"Those plates you made up for the children looked good to me," Faya said to her husband. "Can you make me one while I talk with Zest for a minute?"

"People are going to think I have a hollow leg," Eli said, but he left the desserts with the women and headed back to the buffet.

"What's up?" Zest asked after swallowing a bite of brownie.

"I want to try working independently, like my husband," Faya told her. "I still enjoy the canteen, and maybe I'll work all of my MarsCo days there, but I'm starting to dream about the pie case."

"What were you thinking of doing?"

"It's funny, but even though working in a nursing facility on Earth was hardly my life's ambition, I always got a good reaction from the patients, and it made me feel useful. I was wondering if you think I could do something like that here, maybe part-time."

"I'm nine," Zest said with a snort. "What do I know about eldercare? You should talk to Great Grams." She grabbed Faya's arm with her free hand and began tugging her in the direction of the warmly dressed old lady who Dov had identified as his mother.

"Wait," Faya protested. "I'm not ready to jump in and start working. I just wanted your opinion."

"She'll laugh when I tell her that, and you have to start somewhere. Great Grams looks good, but I know she has trouble with things that she thinks I'm too young to know about. She's also proud of being independent."

Faya stopped resisting Zest's pull on her arm, but as they moved across the room, she asked, "Does your great-grandmother live alone?"

"Ever since my great-grandfather died. All her kids invited her to move in, but she likes it where she is." Zest lowered her voice as they approached the old lady and added, "She has cats, but she's not crazy."

"Zest," the old woman greeted them in a surprisingly firm voice. "Who have you brought to meet me?"

"This is Faya," Zest said, raising her voice to a near shout. "She's a nurse from Earth."

"I'm not a nurse," Faya corrected her, speaking loudly for the old woman. "I have certificates in physical and occupational therapy, and I worked in a nursing home."

"Have you come to take me away?" the old woman asked in mock horror. "You look like you could pick me right up off the floor, but some of my great-grandchildren might protest."

"You two talk," Zest shouted. "I have to run an errand for Gramps." She fled with her plate of desserts in the direction of one of the youth tables.

"That's what she always says when she wants to get away. My name is Agnes, and I was never enthusiastic about all the great-grandmother business, but sometimes you have to let family have their way."

"Please to meet you, Agnes," Faya said, and on a hunch, dropped her voice to her regular speaking volume. "You're not deaf at all, are you?"

"No, but it's amusing to hear them shout, as long as they don't do it in my ear." Agnes patted the empty seat next to her. "Please, sit."

"But you're standing."

"My knees have a way of locking up if I sit too long without heat on them. My son bought me some foam sleeves that help but pulling them on wipes me out for the morning."

"That's how it is with elastic socks on Earth," Faya said, declining the offer to sit. "The people who need them have the most trouble putting them on without help. I know a few tricks, but - "

"Are you interested in a job?" Agnes interrupted. "Forgive me for being blunt, but at my age, I've become very conscious of how much time we all waste on politeness during the middle phase of our lives."

"I'd just been asking Zest if she thought I could find work as an independent caregiver for elders, and she - "

" - isn't old enough to know even the first thing about it," Agnes finished the sentence. "The answer is yes if you have the patience and knowledge to be of use. Everyone my age has a companion robot, of course, but it's better at lecturing me about what I shouldn't be doing than making interesting conversation, and there's something to the human touch."

"We had android companions for the patients in the care facility, and they were extremely helpful for getting people who lacked mobility in and out of bed or a wheelchair. Alpha ran them all, so they were terrific conversationalists."

Agnes gave a dry chuckle. "I'm surprised a superintelligence has the patience to converse with people who may not remember what they've said or heard from one minute to the next, but I suppose artificial life has its own problems. Mine is finding reasons to get out of bed in the morning."

"With all of this family around you?"

"I'm not talking about feeling wanted, I'm talking about being useful. My MarsCo days are down to two hours a week, like a child. I volunteer as a guide in the virtual museum, but I miss playing a larger role in - listen to me talk on and on about myself. I really have gotten old."

"We have a virtual museum?" Faya asked.

"The idea originally came from Earth," Agnes replied. "I think I remember that from my training, though that's going back twelve or fourteen years."

"Yes, we had virtual museums, but Alpha ran all the tours. He always prods visitors to see this or that important exhibit, which takes the fun out of just wandering around and discovering things. I haven't visited one since I got out of school."

Agnes looked over Faya's shoulder and said, "There's a handsome young fellow holding two plates of food who looks hungry enough to eat them both. Why don't you have your dinner, and we'll talk later. As far as I'm concerned, you're hired. I'm a late riser, so come in the afternoon."

As soon as Faya turned around and made eye contact with her husband, he headed for the closest table with open chairs. They both arrived at the same time, and he set down the plates. "Your choice," he offered. "Everything looks good to me."

"Is that cheese in the salad?"

"Somebody told me that it's made from one-hundred percent sheep's milk. I don't know what's in the calzone, but the woman who brought them assured me there's no meat."

"The salad looks too good to turn down," Faya said, taking the corresponding chair. "I always loved dark olives, but I never imagined they'd grow them here."

"Olive trees do well with lots of sunlight and rocky soil, both of which are abundant underground, if you don't mind substituting grow lamps for the real thing," Eli said, slicing open the calzone with the side of his fork. "That looks suspiciously like pepperoni."

"They make a vegetarian version out of dried and pressed tomatoes, beets, and radishes. It's too strong for me."

Eli took a bite and made an appreciative expression. "I guess five hundred Martian years is plenty of time to perfect an underground agricultural system," he said after swallowing. "I've been to a half-dozen farms on service calls, and I'm always impressed by how productive they are. It may be artificial, but there are benefits to controlling the lights, temperature, and pests."

Faya stopped with the fork halfway to her mouth and looked suspiciously at the bit of salad on the tongs. "Do you think they use a lot of pesticides?"

"I don't think they have pests, at least, not in the Earth sense," Eli said. "It would be interesting to look into, as I imagine that plenty must have found their way here in the early days of colonization. But without an ecosystem where pests can escape into the wild, they would have been stuck on the farms, and that's death to unwanted guests in modern farming. Eventually, the farmer will break the breeding cycle, and with no natural reservoir to replace the pests, they go extinct."

"Who'd have thought it would be easier to farm on Mars than on Earth."

"Me," Pat announced himself, taking the seat next to Eli. "I've been delegated to explain our family meeting tradition since Zest is too young to keep a straight face. The long and short of it is that our family, and most of the people living in this burrow, are descended from a religious group, which I suppose people back on Earth might have called a cult. My understanding is that it featured weekly meetings in which members would sit in silent prayer, though occasionally somebody would rise to speak about their experiences."

Eli and his wife exchanged a significant look. "There must have still been quite a few religions on Earth back when Mars was being colonized," Faya said. "What do you believe in?"

"Me, or our forebears?"

"Both."

"I believe in family, work, and not harming others unless they're trying to harm me," Pat said. "Our forebears, well, this is the part where Zest wouldn't be able to keep a straight face. We don't exactly know."

"How is that possible?" Faya asked.

"Thirty-plus generations is a long time, and silent meetings aren't the best way to transmit theology from one generation to the next. Eventually we figured that out, and now everybody talks at Meeting, mainly to keep family relations healthy by making public apologies."

"But don't you have a full copy of Earth's digital libraries on the MarsNet? I've been looking things up in my spare time and I'm amazed by the answers I find. Alpha restricted access to most of that information because he said it was too harmful."

"There was more than one religion featuring public meetings and we don't know which was ours," Pat admitted. "I did a little reading on the traditions it might have sprung from, and I gather that there was a long-running argument over whether deeds or faith could lead a soul to redemption. My suspicion is that our direct ancestors were more concerned with spiritual development than prayerbooks, but I'm hardly a religious scholar."

Eli finished his calzone and poured himself a half-glass of wine from the carafe on the table. "Will there be a formal announcement? Should we bow our heads or anything like that?"

"My father usually says something like, 'It's Friday night, and you all know what that means,' but other times he just starts talking in a loud voice about something he thinks is worth telling and everybody else shuts up."

"Will we be expected to speak?" Faya asked nervously.

"It's strictly up to you," Pat said. "Nobody will think more or less of you one way or another. My sister Eunice never said a word in Meeting until she came home from the U and announced that she was pregnant."

"That must have been a shock."

"All I remember is my grandmother saying that she had a premonition somebody would be needing a baby quilt, but that was her quilting phase, and she was always looking for somebody to unload them on."

"Mom, Dad," Henry said, arriving at the table out of breath. "Avid just told me about a science club where they all build their own telescopes and lasers and go out on the surface to do experiments. There's a meeting tomorrow morning, but I know you were planning to take us all clothes shopping."

"Do you mean you'll be going out on the surface tomorrow?" Faya asked. "Are there any adults in the club, or are all the kids your age?"

"Tomorrow morning is a workshop to build telescopes from kits, and I have enough hours saved to buy one. The club rule is no surface expeditions without two adults, and they don't have any planned this week."

"Who's Avid?" Eli asked.

"Another one of my nieces," Pat told them. "You'll like her. Her family rotates dishwashing responsibilities, and last year she modified an old stockroom robot to fill in for her nights."

"Just her nights? She wouldn't let the rest of the family use it?"

"I don't think it's ever made it through a full dishpan without breaking down. She spends more time fixing the thing every week than it would take her to do the dishes herself. The robot is so old it belongs in a museum."

"I'll get your measurements tonight and pick some things out for you," Faya said to Henry, who was still waiting for an answer. "If the club needs adults for their next trip to the surface, I'd be interested. I didn't get much chance to look around when I was window-cleaning with Zest."

"And I'd be curious to take a look at that robot sometime," Eli said. "Maybe I can offer her some pointers on preventative maintenance."

"Why did it suddenly get so quiet in here?" Henry asked.

Pat indicated the table where his father had just stood. "Meeting time. He must have something he really wants everybody to hear if he's standing up for it."

"It's Friday night, and that means it's time for Meeting," Dov began. "Tonight we have some new friends here, the Booker family, and I'd like them all to stand so I can introduce everybody in one shot." He waited for a few seconds and then continued. "I see Eli and his wife Faya over there with Pat, and I see their son Henry standing with them as well. Where is the mischievous one?"

"Under the table with Deb, Gart, and Aunt Millie's chocolate cake, or what's left of it," a girl called out.

"As long as they didn't drink themselves under the table, the worst that can come of it is a stomachache," Dov said. "The Bookers immigrated from Earth last month, though I'm sure that everybody here already knew that. I've found them to be decent people, and I hope they decide to make our burrow their permanent home. Does anybody have anything to add?"

"I do," Agnes spoke up in her surprisingly strong voice. "Faya just informed me that she was a certified physical and occupational therapist on Earth and worked in a care facility. She's starting a business, and I have first dibs on her time."

All of the grey heads in the crowd swiveled from looking at the matriarch to where Faya was standing with Eli and Pat, and she managed a half-apologetic wave as if to say that the impromptu promotion was none of her doing.

Dov waited a moment to make sure his mother had finished, and then added, "That's all I had to say, so if nobody else has anything important, we can spend some time in silent reflection - "

At least five people started talking at once, and Pat spent most of the next hour quietly filling Eli and Faya in on the context of the testimonies offered by family members. The most touching came from a little boy, perhaps four in Martian years, who had returned to homeschooling lessons a week after deciding that fractions were stupid, and he was going on strike.

"That was lovely," Faya said to Pat after the last testimony was given. "We'll have to think about starting that sort of tradition in our family."

"You could team up with some other families or join ours," Pat said. "I imagine it would get a little stale listening to the same people week after week. My dad has a quiet word with the family members who tend toward over-sharing."

"Speaking of your father, I think he's trying to get your attention," Eli said.

Pat glanced over to where his father was still sitting and shook his head. "No, he wants to talk to you."

"How can you tell?"

"Martian telepathy. That and when he wants to talk to me, he always looks disappointed about something."

A small line of Pat's elder relatives was forming to talk with Faya, so Eli made his way alone to see Dov.

"Your son explained the family meeting tradition to us," Eli said. "It was very touching."

"We have good weeks and bad weeks," the old man said with a shrug. "You don't want to be here if somebody is having marital difficulties. But now let's talk about you."

"After that great welcome, are you going to tell me it's time to move on?" Eli asked. "Hearing myself praised did remind me of some retirement ceremonies I attended on Earth."

"Did they have one for you?"

"I basically slunk off with my tail between my legs."

"And uprooted your family and children to move to a planet that you knew almost nothing about," Dov said. "I'm hoping that you've been here long enough to trust us - trust me - enough to tell me if there's something I can do to help. I used to be a pretty good judge of men, and I can't shake the feeling that you're carrying a heavy load, even though I rarely see you without a smile."

Eli bobbed his head and came to a quick decision. "Do you know any higher-ups at MarsCo you could put me in touch with? I was going to procrastinate asking for another week or two, but there are people back home who would say I've already waited too long."

"Is this a business thing or something serious?"

"It's not business. There are things happening on Earth that you should be aware of, and - "

Dov held up a hand to stop him. "I'm retired, I'm getting too old to keep a secret, and if I don't have a need to know, you shouldn't tell me. I do have a friend on the board, so I'll drop a word in her ear. I'm sure she'll have somebody who deals with planetary security get in touch with you as soon as possible."

"Which board?" Eli asked.

"I served five years on the MarsCo board of directors," Dov told him. "It's the only board that runs such long terms because there's just too much background material to master before you can take part in strategic decisions."

"How long do most directors serve?"

"Five years is it. That's Martian years if you're still thinking in Earth terms. One of the fundamental principles of MarsCo's structure is to cycle as many stakeholders through executive positions as we practically can without making a hash of things. There are some technocrat jobs related to terraforming and infrastructure where an experienced manager can stay on for decades, but we wanted to avoid the deep state issues that we see in other colonies."

"Do you think you've succeeded?" Eli asked, carefully watching the older man's face.

"As much as is possible," Dov replied. "The advantage MarsCo has going for it is that we're following a plan that everybody on the planet agrees to - agrees to or moves on elsewhere. And that plan, to terraform Mars, is complete with easily measured milestones and clear objectives that stretch so many generations into the future that nobody trusts a fast talker with easy answers."

Twelve

"Pause lesson," Liza said when her mother entered. "Is it time for art workshop?"

"We have a few more minutes," Faya said. "I thought I'd just check in on how you're coming along with your Mars Studies course."

"It's so easy. I've started reading ahead so I can almost tell you what the teacher is going to say before she says it."

"Wouldn't it be more interesting if you watched the lesson first and then read the coursebook on your tab?"

Liza shrugged, an exaggerated gesture she'd copied from Henry. "I used to do it that way, but Gart told me he had trouble understanding the lessons until he started reading them first, so I tried it. Do you want to watch with me?"

"What are you learning?"

"About the maglev system. Did you know that the dulls float over the track because they're magnets?"

"Maybe we should watch a little together," Faya said, sitting down on the corner of the bed near where her daughter was sitting cross-legged on the floor. "I'm not sure that's the whole story."

"Continue lesson," Liza said, and a hologram appeared showing a simplified version of the maglev system.

The dull appeared to have a giant cartoon magnet on the back, one half of the horseshoe colored blue, the other half red. Below the dull was a single wide rail consisting of horseshoe magnets standing in a row, all of them displaying the same blue and red color pattern. The blue side of the magnet on the dull was above the blue side of the U-shaped rail, and lines of force that bent back on themselves due to repulsion were depicted between the two.

"The magnets in a maglev system serve two purposes," the voiceover continued from where it had left off. "Here we're showing how they keep the dull floating above the track."

"I told you they were magnets," Liza interjected triumphantly.

"Dulls are also propelled by magnetic fields," the voice continued, and the hologram changed to show a bottom view of a dull, this time a giant bar magnet stretching the length of the undercarriage. "In this simplified model, the north pole of the magnet faces forward, and the south pole faces backward. If you were in front of the car with a magnet, which pole would you point toward the dull to pull it toward you?"

"North, I mean, south," Liza said. "Maybe I should be an engineer like Dad."

A giant magnet with the south pole pointed back toward the dull appeared in front of it, and the car began to move. "For twice the power, we'll put another magnet behind the car to push," the voice said, and another giant bar magnet appeared behind the dull. "In practice, rather than using horseshoe and bar magnets, maglevs are built with superconducting loops that create magnetic fields, just like the MarsLoop that protects our planet from solar radiation."

"Pause lesson," Liza said. "She's always doing that, explaining how something works, and then saying that's not how they actually build them. That's why it's confusing if you don't do the reading first."

"But I just learned something," Faya said. "I knew that the dulls floated on magnetic fields, that's where the maglev name comes from, magnetic levitation. But I didn't realize the car was propelled forward by magnetic fields as well."

"Maybe," Liza said. "Or maybe when I'm Henry's age and get the grown-up explanation, they'll say that the dulls are really pushed by ghosts. That's what Gart says."

"Does he talk a lot about ghosts?"

"All the Martian kids do. They say that everybody who dies on Mars becomes a ghost because they can't return to Earth."

Faya sighed. "Just don't let anybody convince you to do something dangerous because they say that a ghost wants you to. And we probably should get going now. You can finish the lesson later."

"I'll get my art supplies," Liza said, uncoiling from the floor like a striking cobra. "We're doing watercolors today."

After dropping Liza off at the park for her art group, Faya continued down the blue tunnel, consulted with her comm, and then navigated two side tunnels to reach a round door made from wood and set into the rock wall. There was no sign of a bell or camera system, but a black iron hammer rested on a striking plate in the center of the door, so she lifted it on the pivot point and let it fall with a bang. After a minute passed with no response, she began thinking of hammering again or comming her new client, but then the door opened inward.

"Welcome to my hobbit hole," an elderly man in a wheelchair greeted her. "You'd think that rolling would be superior to walking, but as you can see, it's an obstacle course in here."

"It is a bit cramped," Faya said in dismay. There were stacks of everything imaginable forming a sort of maze in the apartment, though fortunately, she could see over the mounds as they had been built by a man in a wheelchair. "You must be Mario."

"Guilty as charged," the man said and extended his arm. "First things first. Clock in, and then you're mine."

"Uh…" Faya hesitated for a moment, but the old man's smile looked genuine, and Agnes had vouched for him. 'Visiting Rehabilitation Services clocking in." She swiped her token arm over his.

"I accept," Mario confirmed after the beep. "Now, before you lecture me about being a hoarder, I know where everything is, and you're looking at important research materials that I can't part with. When I'm gone, my children can take it all to the recycling center."

"I wouldn't dream of lecturing a client. It's just that - do you need help turning the chair around?"

"It would save me a ten-point turn. I usually go out into the tunnel and circle back."

"But how do you get the chair through a round doorway?" Faya asked as she tilted it back and spun it around.

"There are two large climbing gears you can't see - this chair can go up a staircase. But my last physical therapist suggested I use the manual drive wheels at home to try to regain some arm strength."

"Is there an area where we would have a little room to work?"

"The kitchen," Mario said. He applied a downward force on the push rims with both hands to shoot forward. Then a stack of plastic boxes forced him to stop and do a slow turn like a skid steer. "My daughter won't let me store anything in the kitchen other than food."

"Does she live with you?"

"Heaven forbid - she's on the other side of the planet along with my ex-wife and the rest of that crowd. But I have a very nice grandson who's married to a granddaughter of Agnes, so the whole clan has a claim on telling me what to do. I try to keep my head down and never complain so they forget that I'm here."

Faya laughed. "You aren't the first client I've had who's figured out that compromise. Back in the care facility on Earth, I had patients who neglected to tell their families that they had remarried. It's strange how some grown children seem to confuse supporting their aging parents with dictating to them."

"This way," Mario said, shooting the gap between a large robot of a type that Faya didn't immediately recognize and a more standard companion model that could lift somebody out of a wheelchair, support them in a shower, or put them in bed.

"I see you have a companion, but what's the other robot we just passed?" Faya asked as they entered the bright kitchen area. It was so sparkling clean that one of the robots must have taken over maintenance.

"That robot, my good therapist, is the focus of my recent research. It's an independent exploration model, and while nobody believes me, it's alive."

"You mean artificial intelligence?"

"I mean a self-aware machine," Mario said. "I've put in my Will that it's not to be sold or recycled after I'm gone. I researched the necessary precedents in old slavery laws from Earth that will allow me to manumit E49G22 on my death."

"But not before your death?" Faya asked.

"He prefers that I wait, and to be honest, I couldn't bear it if my Will doesn't stand up. You'll talk to him on another visit, but right now, he's meditating."

"Then we'll move on to you. When's the last time you got out of this chair under your own power?"

"I'd have to think," Mario said. "My last birthday? Or maybe it was the one before?"

"So as much as a Martian year if not longer," Faya said.

"That sounds fair, but I work with the companion to maintain the strength in my legs. It's just that I'm not confident about standing without support, and breaking a hip gives you a new and darker perspective on life."

"You fell?"

"The hip broke and then I fell," Mario explained. "I've been taking nanobot injections to rebuild my bones, and the doctor claims they're more resistant to breaking now than they were ten years ago. But my confidence…"

"I understand. I'm not going to push you into taking chances in our first session, but I would like to see you try to rise, at least part way, with my support," Faya said. "That will give me an idea of how much work we have ahead of us."

"Agnes said that you're as strong as a robot so I guess we can do that. Will you be in front of me or behind me?"

"Beside you. I couldn't have done this in my last job because it would have been too much weight for me to support on one side, but gravity here is a fraction of what it is on Earth, and you're all skin and bones."

"Nice bedside manner," Mario said sourly, maneuvering his chair for the maximum open space in front of him, which meant getting the back up against the refrigerator. "I used to be an athlete.

"I'm so sorry," Faya said. "It just slipped out, and everybody I've met on Mars seems to say whatever is on their minds."

The old man looked up at her and suddenly smiled. "Truth be told, I was a marathoner, and I never could do more than a dozen push-ups in my prime."

"I'd like to have something for you to hold onto once you're up to see you standing under your own power. Can you summon your companion and have it extend the walker bars?"

"I know where this is going," Mario said with an exaggerated sigh. "You're going to try to convince me to start exercising, even though we both know that I'm too old to recover any significant strength. Well, I'll go along with you for the entertainment value, but don't expect me to buy into the belief that I'll be running marathons again in no time."

"I won't," Faya said. "It's nice to work with somebody who doesn't have unrealistic expectations. At least half of my physical therapy clients on Earth started out with great enthusiasm but gave it up as useless within a few weeks. At this age, setting a goal is more about preserving what you have left than building up to competitive sports."

Mario nodded. Without turning his head back toward the cluttered living room, he called, "Basil. In the kitchen."

"Basil? That's an interesting name for a companion robot."

"E49G22 came up with it."

"Your other robot named your companion, yet it prefers the manufacturing code for itself?" Faya asked.

"I'm surprised you recognized it as such," Mario said.

"My husband is a robotics engineer." She jumped back in surprise as Basil rolled in between her and the chair. "Oh! You have the quietist companion bot I've ever encountered."

"E rebuilt him from scrap. Your husband would be surprised by what's inside."

"Can you ask Basil to extend his walker grips?"

Mario grinned. "Basil. Break out the walking gear."

Twin hatches on the robot's upper torso opened up, and a stubby pipe with a diameter that looked too large for the old man to grip extended from each port. Then a slightly smaller pipe telescoped out of the larger, and the process continued until there were two standard-sized grips almost an arm's length away from the companion's body.

"I've never seen that trick," Faya said. "Most companion bots have a one-piece yoke attached to the front that folds down when not in use."

"I told E to apply for a patent, but he said it's been done before, though not as well." Mario eyed the ends of the extended arms. "So how do I get from here to there?"

Faya crouched, puzzled over the wheelchair footrests for a moment, and then figured out how to fold them back out of the way so that Mario's feet were touching the floor. "Let's apply the brakes and slide you forward a bit - good," she added as he took some of his weight on his arms and skidded his butt forward so his feet were flat on the floor. "Now, hands on the arms of the chair, lean forward to get your weight over your knees - how do you feel?"

"Silly."

"That's fine, I won't tell anybody. Are you ready, or should I count to three?"

Mario pushed up on the arms of the chair while trying to stand, and Faya took some of his weight to ease the process. He hesitated at the point where he was in a crouch but still holding onto the chair, and then moved one hand to a support extended by the companion bot before straightening up and moving the other hand. Even though he stood with a definite stoop, he was a head taller than Faya.

"Don't praise me for getting out of a chair," he warned her. "I may be out of shape, but it's something I could do at the age of one."

"One? Right, you mean two, or I mean two," Faya said. "How do you feel? Any dizziness? Do you need to sit back down?"

"I'm on my feet every day when Basil helps me get dressed. It's just that I let him lift me out of the chair or off the bed."

"And the toilet?"

"A gentleman never tells."

"Suit yourself," Faya said. "Do you think you can stand on your toes? That's good. How about rocking back on your heels?" She carefully watched his center of gravity even though he had both hands on the support. "Don't worry, I won't let you fall. Up on the toes, back on the heels. Let's see if we can do it ten times."

"You're getting cheerful on me," Mario complained as he rocked back and forth. "Is this what passes as exercise with people my age? No wonder we're all in such bad shape."

"You're starting to sound ambitious," Faya said. "As long as you're up, shall we try something a bit more challenging?"

"Jumping jacks?"

Faya laughed. "Let's take it a little slower than that. How about reaching back with your left foot as far as you can, so it ends up on the toes under the wheelchair."

Mario leaned visibly on the support arms extended from the companion robot as he did the move and then brought the foot forward again. Then he extended the right foot behind him and brought it back without being told.

"No discounts for second-guessing me," Faya told him with a smile.

"You're on the clock," Mario concurred. "How many should I do?"

"Let's start with five, and if you can hold the stretch for a few seconds, that would be good."

He finished the set without further banter, at which point his arms were shaking a little, but he asked, "What's next?"

"How do you feel?" Faya asked, casually taking hold of his wrist, but her forefinger wrapped around to the artery where she could feel his pulse.

"I know what you're doing, and nobody my age has heart attacks on Mars," Mario said. "The ones with the wrong genetics or horrible diets get them early, but by the time you're forty or so, the heart generally fails in a less spectacular fashion."

"I don't want it to fail at all. An elevated pulse is normal during exercise, so if you feel alright, we can try one more."

"Jumping jacks?"

"I was thinking about taking your foot out to the side as far as you can reach and pointing the toe," Faya said. "Let's give it a try."

On the third repetition, Mario's straight leg started shaking, and he seemed to be leaning a bit too far toward the extended foot. Faya stepped right up against him and supported him with her right arm. "Reach back for the arms of the wheelchair, one hand at a time," she instructed him. "How do you feel?"

"A bit winded," he admitted after dropping onto the seat. "Basil never asks me to dance while I'm standing."

"Now comes the part that everybody hates," Faya said, retrieving her tab from her purse. "I'd like to ask you some questions about your current limitations and what ambitions you have for physical therapy."

"You mean, like going for a hike on the surface?"

"We could make that one of your stretch goals, but I was thinking more along the lines of moving around your home without the wheelchair."

Fifteen minutes later, Faya was just putting away her tab when her comm beeped, informing her that they were nearing the end of the half-hour visit.

"I may be old, but that wasn't an hour," Mario grumbled.

"I work in half-hour increments."

"That's crazy. You'll waste all your time running between clients. If you're going to work in such short stints, you should charge double-time."

"I didn't know that was possible. I'll have to think about whether I'm comfortable with it."

"Don't sell yourself short," Mario told her. "I'm not a charity, and neither are any of my old friends, where old is the operative word. I'll let you off this time since you didn't know any better, but if you come back, I expect a minimum one-hour charge. I'm surprised Agnes let you get away with it."

"I spent almost two hours with her, though I shouldn't really be talking about my other clients," Faya said, and she reddened slightly. "All right, we'll do it your - " she broke off with a sudden intake of breath when she realized that the old explorer robot was standing in the kitchen doorway with its cameras trained on her, and no doubt listening to the conversation.

"E," Mario addressed the robot. "You startled our recent arrival from Earth."

"I was built on Earth," the robot replied conversationally, though its voice had a mechanical sound that was no doubt intentional. "Forgive me for appearing this way, but I heard the two of you talking and couldn't contain my curiosity."

Faya realized that she was staring at the robot with her mouth hanging open, and finally blurted out the first thing that came to her mind. "My husband is a robotics engineer. Perhaps I could introduce you sometime."

"I'd like that," E49G22 said.

All the way to her next client, Faya replayed Mario's references to the exploration robot in her head, trying to figure out if it was all an elaborate prank arranged by an old man who had too much time on his hands. In the end, she decided to pass the exploration robot's invitation to Eli and let him decide. Then her wristcomm announced that she had arrived at her destination, and she waved a hand in front of the lens embedded in the door. A few seconds later, it slid open, and she was ushered in by a spry old woman wearing a cheerful frock.

"Come in, come in. Agnes told me that you're a positive angel and I've been so looking forward to your visit."

"Since we talked this morning?" Faya asked, mentally biting her tongue when she heard how snarky the response sounded. "I didn't mean - "

"Not at all, dear," the woman interrupted. "You already know that my name is Paula, but I'll introduce myself just the same. Paula Eleven."

Faya shook the proffered hand, and said, "That's a lot of you, though I know a Zest twenty-six."

"Yes, and she never lets anyone forget it," Paula said with a laugh. "Still, I must admit that Agnes has been lucky in her descendants. A few of mine have left Mars for the moons of the gas giants, and one even tried to return to Earth, though last thing I heard she couldn't stand the gravity and was waitressing on the Moon."

"My husband was there once on a repair job," Faya said. "Hopefully she'll earn good tips."

Paula gave a quick nod, a strangely bird-like movement, and then she asked, "Do you play contract bridge?"

"I don't even know what it is."

"That's a shame. Can I get you a cup of tea? Cookies? I was up early baking a batch of gingerbread cookies. My grandchildren complain that they're too soft, but I prefer them that way for dental reasons."

"I would like that - but wait," Faya interrupted herself. "I'm supposed to be here to work."

"Where are my manners," Paula said, extending the arm with her comm and token. "I was so excited about having new company that I forgot."

"Right. Visiting Rehabilitation Services clocking in."

"I accept. But that is an awkward sort of business name for you to be saying all of the time, don't you think? Perhaps you could shorten it to VRS and only spell it out if somebody asks."

"Will that work for the comms and tokens?" Faya asked.

"It may ask you for clarification the first time, but the token network is run by artificial intelligence, and while it's not self-aware or smarter than the average person, it makes up for that with memory and storage," Paula said. "I was a permanent employee of MarsCo, and I worked in MarsNet applications development for most of my career."

"I'd love to hear about that when I'm off the clock, but for the next hour I have a professional obligation to provide you with some therapeutic value for my time."

"Are you saying I need to invent something wrong for you to come? Let me see. I really can't complain about anything physically, other than the fact I only sleep around five hours a night, but that's common with some elder folk, at least on Mars. I'm not depressed that I'm aware of, but I have noticed that I'm up and down every few minutes peeking through the oven window whenever I'm baking. Maybe I'm developing obsessive-compulsive disorder?"

"I don't think checking on your baking would qualify as a form of mental illness," Faya said. "When we commed earlier today, you told me that you're not getting out as much as you used to."

"Yes, but that's primarily because I don't have as many places to go. One loses quite a few friends to mortality as one ages, and as much as I like the desserts at the canteen, going there every day would just make me look lonely."

"Do you worry about looking lonely?"

"Of course, dear. Every day I check the mirror when I get up and it seems to me that I look exactly like myself. But sometimes when a young relative or acquaintance turns to look at me, there's a brief moment when I see pity in their eyes."

"I'm not going to suggest that you're imagining it because I'm sure you're a better judge of your friends and family than I am. I can say that when you let me in, my first thought was how well you looked."

"In context," Paula said. "I look well for a forty-seven-year-old woman who hasn't worked full time in over ten years."

Faya rapidly did the math to determine that her new client was around ninety in Earth years and had retired at seventy.

"Does MarsCo have a mandatory retirement age?" she asked.

"No, but they begin limiting the hours you can work after forty. I had a management job in the end, a sort of mid-level technocrat. As long as I remained in the position, my assistant could never move up, and when he turned thirty-two, I realized that I could best serve MarsCo by vacating my place for him before he was too old to make the transition."

"You don't have any physical or mental challenges that you're aware of?"

"Keeping busy," Paula said. "I think you'll find it's a common complaint."

Thirteen

"Can I go with you?" Henry asked his father. "I haven't been out of the burrow in weeks."

"Are you all caught up with your courses?" Eli asked.

"They don't have deadlines or anything, but supposedly I'm on track to finish all of my requirements to attend the U by the time I'm eight."

Like his wife, Eli still hadn't adjusted to the Martian calendar and took a moment to realize his son was talking about finishing the equivalent of high school before he was sixteen.

"MarsCo does a take-your-daughter-to-work day, and I was going to bring Liza along next time I work at the Canteen," Faya said. "I think that people here must be used to parents showing up at work with a child in tow."

"I'm hardly a child," Henry protested. "I'm almost seven."

"I suppose the worst that can happen is they'll ask me to send you home, and you're old enough to navigate the maglev," his father said. "All right. Grab your tab so you can do some reading in case you get bored. It sounded like a software issue."

"Can I carry your tools?"

Eli hesitated for a moment since he hadn't even been planning to bring his full field service kit. On Earth, it would have been forty-odd pounds of tools and hardware that would have been too heavy for the boy, but on Mars, the weight was easily manageable. "It's a deal," he said.

On the way to the regional MarsCo robot repair facility two burrows over, Henry filled his father in on the progress of his telescope project. He was looking forward to trying it out on the field trip and asked again if his father would consider coming as an extra adult supervisor.

"It wouldn't be fair to the other kids if your mother and I both went, not to mention Liza feeling left out. And I haven't been on the surface yet, so I'm not qualified to supervise anybody. Your mother has done a few MarsCo workdays outside with Zest and they're used to working together as a team."

"Does Zest count as an adult? She doesn't talk like one."

"You don't think so?" Eli asked as the dull came to a halt. "I'm usually impressed by what she has to say, but maybe she talks differently depending on her audience."

"Maybe," Henry said as he lifted the field service pack and followed his father out of the dull. "Wow, this tunnel is huge!"

"It's certainly bigger than anything in our burrow. The first time I saw it I couldn't help thinking that it's big enough to move a small spaceship if the maglev system can handle the weight." Even as he spoke the words, Eli had a premonition that he'd stumbled on the exact reason the tunnel was so wide. He glanced over the edge of the platform and saw that there was indeed a second, much larger maglev rail in the center of the tunnel.

"Are we switching to a dedicated maglev running to the MarsCo service center at the atmo station?"

"I think it's a regular loop," Eli told his son as he started walking toward the smaller tunnel that ran in parallel with the larger one, a platform separating the two. "They probably have the big MarsCo emblem painted on the wall for people who have never brought robots or equipment to the repair facility."

"But wouldn't their comms tell them where to go?" Henry asked.

"Yes, but sometimes it's nice to have real signs like we did on the corridors back home so people aren't one hundred percent dependent on the software. And speaking of the devil, that's an impressive piece of code."

"What is?"

"When we got to the maglev tunnel in our burrow and I summoned a dull with my comm, I gave it our final destination," Eli said as a new dull came to a halt a few steps away. "The software must have waited until it had a high confidence in our arrival time to order us a transfer dull on the local loop." He stepped through the open doors and waited for his son to join him. "Timed it within a few seconds."

Henry shrugged. "I don't know why that should be complicated. I think I could describe the steps well enough for a code generator so long as I wrote it down first."

"Remind me when we get home and maybe we'll both try it," Eli said. "The problem with programming by providing a functional description to a code generator is that it can only do what you tell it. When I want to program a new routine for a robot, something out of the ordinary, I usually find I can code it faster by writing the framework myself and only using the code generator for the objects and subroutines."

"Why don't you spend more time describing the framework you want in the first place?"

"It's a trade-off. To describe precisely what I need would be to completely define the program, which is essentially the same thing as writing it myself. I like coding so I kept in the habit, but I always suspected Alpha of replacing the code I wrote with his own."

"Oh." Henry thought for a moment and then asked, "Do all engineers know how to code?"

Eli shook his head. "I was the only one I knew who bothered learning. The code generators here on Mars are a limited form of artificial intelligence, but on Earth, Alpha was behind all the tools, and he's better at coding than any human could be."

"Kids in school thought it was weird that you were teaching me. Everybody said it was a waste of time."

"Maybe someday humanity will reach a point in science and technology where we can't go any further, but if it happens, it will be because we've given up trying."

"Are you saying that it's impossible to know everything?" Henry asked.

"For us it is," Eli said. "For a superintelligence like Alpha, I'm not so sure." The doors opened on a brightly lit platform. "I don't want to give you an overly simple answer to a complex question, but I've seen mathematical proofs that perfect knowledge of even the simplest systems depends on assumptions that aren't necessarily universal. It means that if you completely understand the technology powering that dull we just arrived in, you probably can't use the same rules to describe what you see when you look at your mother." He held up a hand to forestall his son's objection. "I know that maglevs and mothers sound like two unrelated systems, but wait until you take a survey course on Alpha's technical innovations at university. You'll wonder why we don't just wave our hands and say everything runs on magic."

"But…"

"Eli," a woman in her mid-thirties greeted them, striding forward to greet the pair. "Welcome back, and it's good to see you brought an assistant this time. We just got an emergency repair order in, and our two techs who work on space construction robots are on the other side of the planet for a conference."

"I'm not sure I was aware that Mars had an orbital construction program, but given what I've learned about your relations with the other colonies, I guess it makes sense," Eli said. "This is my son, Henry."

"Pleased to meet you," the woman said, offering a handshake. "I'm Alys, and I handle the scheduling at the repair facility. It's this way."

"We're not going to the central workshop?" Eli asked as she led them down the platform, away from the main entrance.

"We maintain several smaller workshops for experimental work and rush orders," she explained. "I'm sure I don't have to tell you how confusing things get when you have parts from multiple robots scattered all over the same space."

"Don't you have workbenches?" Henry asked.

"Ideally, every repair job gets its own workbench, but if there's a part on back order or a problem that requires the attention of a specialty tech, the central workshop starts getting cluttered in a hurry. It's not that unusual for the techs to cannibalize a low-priority repair for parts to complete a rush job, but that means even more bench time for the robot that's serving as a donor. We end up with several R.I.P.s a year."

"It's like a funeral when you use an old robot for parts?"

Alys unconsciously slowed her pace while she considered Henry's question. "Ah, I see what you're saying, but R.I.P. is an acronym that means 'Removed Important Parts,' which often leads to the robot being scrapped. You can keep any machine going indefinitely with enough parts, but at some point, it's more efficient to replace it with a new one from the factory. And here we are."

"Thank you," Eli said as the door slid open to reveal a brightly lit pedestrian tunnel. "Have you updated the locks for my token? It would be a shame to have to comm you to come rescue us if there's another door around that next turn."

"The scheduling software updates all of the relevant locks for your token, and there is another door around the curve," Alys said. "You'll have to open it if your son goes out because he's not in our system. If he needs to go back and forth, I can add him."

The workshop proved to be much larger than Eli would have expected, with a large airlock leading to a freight elevator at one end. A space construction robot, whose armored hull showed signs of pitting from micrometeoroids, was resting in a work cradle, though it wasn't clear if it had gotten there under its own power or by way of the overhead hoist whose track extended to the airlock.

Henry set the field service kit on the workbench next to the cradle and examined the robot. "What's wrong with it?" he asked his father.

"There should be a work order or a failure report around here somewhere, but I don't see one," Eli said. "Alys did say it's an emergency job, so maybe the documentation trail hasn't caught up yet. Stand back by the door just in case, and I'll check and see if it threw a code on the service display."

"Why should I be near the door when I can't open it?"

"That's a good point," Eli said, shooting his son a grin. He walked over to the door, swept his forearm with the token past the sensor, and then stood in the opening for long enough to ensure that the door wouldn't start to close. "Come here and take my place," he told Henry. "I wouldn't do this if it was a primitive controller that kept trying to close the door, but it must be using a system that detects objects in the way."

"If the door cuts me in half, you have to tell mom," Henry said, swapping places with his father. "What should I do if the robot goes berserk?"

"It won't, but if you think anything is wrong, step out into the tunnel and let the door close." Eli went back to the robot and used his multitool to open the manual access hatch before adding, "Keep in mind that I'm doing this based on my years of experience. If you ever come across a non-functioning robot, don't try to turn it on just to see what it does."

"I know that. I'm not a child."

The controls were almost identical to the standard orbital construction bots Earth had once produced for Ark construction, and the display was active and showing several failure codes, some of which Eli recognized, some that were new to him. "Alright, you can come back in," he called to Henry. "This one was in the process of switching from its primary power cell to the backup when something went wrong and invoked an emergency shutdown. I'm not going to try to power it up until I figure out what the other codes mean."

"Why do robots display codes instead of telling you in plain English what's wrong?" Henry asked, coming over for a look. "Why display text at all rather than just talking?"

"Space construction robots don't have speakers because sound waves can't propagate in a vacuum, and codes are a concise way to display the status to a professional who's familiar with the equipment. I took a history of technology course many years ago - I think you'd like it if the homeschooling curriculum has an equivalent - in which they talked about how archaic practices can become embedded in modern technology. At the dawn of the electronics age, there were no text displays, so errors were encoded as a series of beeps or a blinking light. Then they developed small character displays that could show a few numbers or letters, but each character added to the expense, so error codes were intentionally kept short."

"When the world was ruled by kings?"

"After that, I think. But more than a thousand, I mean, five hundred Martian years ago." Eli tapped his comm, brought up the technical library app for MarsCo, and read off the error codes.

"Primary power switching solenoid failure," the comm translated. "Primary power circuit failure. Secondary power circuit failure. Emergency backup power unavailable."

"That sounds like a lot of problems," Henry said.

"It could be, but if they're all the result of the switching solenoid burning out or getting jammed, that's an easy fix," Eli said. "It's like that with cascading errors sometimes. The diagnostics were smart enough to list the solenoid first since that's likely the root cause, but it also knows that both primary and secondary power aren't online, and that the emergency backup isn't available."

"Then how does the diagnostic system work?"

"It's got its own encapsulated power system, usually a battery trickle charged by a photovoltaic cell, and it doesn't switch on until all else fails. Let's pop the main power hatch and get a look at the switching solenoid."

Five minutes later, shining his flashlight in the space between the power cells, Eli felt a chill run down his spine. "I'm going to need some number two welding cable and I don't have any in the kit," he told his son. "Do you think you could run back to my shop and get it while I take this apart?"

"Sure, Dad, but you'll have to let me out," Henry said. "Does this mean I'm on the clock?"

"I guess it does, but let's just settle it off the books." He walked Henry to the door, scanned it open, and didn't even blink when he saw a man coming up the narrow tunnel toward them. "And if you happen to go by the Canteen on the way, I'll pay you back for a large black coffee and whatever you're having."

The prospect of a second breakfast consisting of pastry put the wind in the boy's sails, and he ran down the tunnel without a second look at the new arrival. Eli remained standing in the door to keep it from closing until the stranger slipped through with a nod.

"Jace, as in my mother liked the name," the new arrival introduced himself as soon as the door slid shut. "Forgive the cloak-and-dagger routine, but you reached out to us without many details, so I decided to play it safe."

"You're representing my friend's friend?"

"Good, there's no point getting other names involved at this point," Jace said approvingly. "In an indirect manner, I am. But I'm also your case officer." He let out a low chuckle when he saw Eli's surprise. "No, you haven't done anything to attract attention, other than being the first person from Earth to show up here with a family in tow for longer than I've been on the job."

"Can I ask what job that is?"

"Worrying about the future," Jace said. "To be more specific, worrying about what Earth will do in the future, since there's twenty billion of you and around two hundred million of us."

"Well, that's the first time I've ever opened up the case of a space construction robot and found a disconnected solenoid and a piece of tape with, 'I'm at the door,' printed on it. Your timing was several seconds off," Eli said with a forced laugh.

"Your son threw me. I gave you a little extra time to come up with an excuse to send him on an errand."

"I'm impressed. What else can you tell me?"

"You're the one who asked for this meeting."

"But if you fill me in on what you already know, I won't waste a lot of time trying to keep it hidden from you," Eli said. "I'm not in the worrying profession myself, but I role-played various situations to prepare for this trip, so I know how long a conversation can stretch when both sides are trying to hide something."

"Fair enough, with one caveat," Jace said. "I'm making the assumption, I think a well-based one, that you aren't here as a spy. If I change my mind about that later, I'm afraid we'll have a problem."

"I understand," Eli said and gestured toward the pair of stools next to the workbench. "I'd just as soon be sitting down, if you don't mind."

"Did you reconnect the solenoid?"

"Not yet."

"If you'll allow me." Jace walked over to the cradle, snapped the solenoid leads back into place, and moved the tape with the message so that it now foiled the safety switch that prevented the robot from powering up with the hatch removed. Then he hit the master reboot, and there was a clunk as the solenoid physically reconnected the main power and the robot activated.

"Can I assume that despite being designed for the vacuum, this robot is equipped with a microphone and will now respond to your voice commands?" Eli asked.

"It seemed like a reasonable precaution, in case an accident is required," Jace said agreeably. "And your familiarity with space construction robots is striking for a man from a planet that canceled its space program before my father was born."

"There's still the Moon resort."

"And the last Ark that was abandoned in orbit before construction could be completed. I took the liberty of obtaining a DNA sample from a robot you worked on a couple of weeks ago, and it confirmed my suspicion that you are a direct descendent of your namesake. That you didn't come here under a false identity is one of the facts litigating in your favor."

"You have my great-grandfather's DNA on file?"

"You didn't know that all of the crew and passengers leaving the solar system in Arks were required to give DNA samples for the public database?" Jace appeared genuinely surprised by Eli's blank look. "It may be thousands, even tens of thousands of years before the various branches of humanity make contact again, if ever. Keeping a DNA record of those who left for future identification made a lot more sense than amassing a record of everybody staying behind."

"I'm not sure why it's necessary in either case, but you're correct I'd never heard that. We have community stories about the Arks that are passed from one generation to the next, but Alpha doesn't answer questions on the subject."

"Where does a superintelligence sit?" Jace asked rhetorically. "Anywhere it wants. I didn't have any first-hand knowledge about Alpha's censorship until now, but it makes sense that after he shut down the Ark program, he'd want it to fade from memory."

"You're interested in Arks?" Eli asked.

"In the Arks themselves, very little. Mars isn't in a situation where we can stock an interstellar colony ship and send a million individuals off on a multi-generational journey with no expectation of hearing back unless it's a complete disaster and their tenth-generation decedents return to the solar system with their tails between their legs."

"It's impossible for the Arks to communicate while the reactionless drive is activated, and it's an unnecessary risk to disengage for something as frivolous as trying to send a message home."

"So you did retain some knowledge in your family," Jace said. "I was beginning to wonder if Alpha's information suppression techniques were so pervasive that parents were afraid to talk with their children."

Eli looked up sharply. "My grandfather waited until I was in my twenties to talk to me about what his father had passed on. That is, what he remembered of it."

"And your father?"

"He died working on the Ark when I was a child. I suppose it's one of the reasons I got into robotics. His death just seemed so unnecessary when a robot like that one - " he pointed at the maintenance cradle, " - could do the work faster and better without any risk to life or limb."

"Our traders who are allowed into Earth orbit have reported that work on the Ark is underway again, including with space construction robots," Jace said.

"That's right, but the robots aren't working autonomously. There's no built-in artificial intelligence and Alpha won't control them like in the old days. Each and every one has a remote operator in our community on Earth, essentially a servomechanism setup."

"I didn't know that, so I'll give you something in return. Mars doesn't have any spies on Earth, and neither do any of the colonies that I'm aware of. We decided that giving Alpha reasons to be paranoid was a greater risk than conducting our policy with incomplete knowledge."

"It never even occurred to me that Mars might be spying on Earth," Eli said with a frown.

"We're meeting in this manner and place because Alpha does have agents on Mars. We keep tabs on the ones we're aware of, but we don't otherwise interfere with their work. MarsCo would prefer if the information flowed both ways, but most of our progress here is based on technology that was originally developed on Earth, so we don't begrudge giving something back."

"I thought the biggest adjustment we'd have to make on Mars would be the gravity, but the thing that keeps hitting me in the face is the contrast between how Alpha runs Earth versus how MarsCo runs Mars."

"It comes down to different goals," Jace said. "Alpha runs Earth with one objective, to remain in perfect alignment with humanity, though Alpha alone knows what that means. Maybe when our terraforming work is completed, we'll run into the typical governmental problems, but thanks to tradition and education, every man, woman, and child on the planet is on the same team." He paused, and then looked directly into Eli's eyes. "You requested this meeting for a reason, and I was dispatched to hear you out. Are you comfortable that I am who I say I am, or will we need to do this differently before you're ready to tell me why you're here?"

Eli nodded slowly. "If I seem overly cautious, it's because I'm here representing a community, not just myself. Are you familiar with how the crews for Arks prepared for their journeys?"

"They were isolated in rural areas with no access to resources other than those they would have on the Ark, and anybody who left wouldn't be let back in," Jace said. "I read some on the subject because I thought it was a fascinating way to…" He trailed off and his face took on a strange expression, somewhere between respect and pity. "Three full generations since the program was shut down? Your community has remained isolated this whole time?"

"Arks aren't constructed in just a couple of years. Even when there were millions of space construction robots working on them under Alpha's control, a couple of decades of isolation was traditional. Alpha may have lost interest in interstellar exploration, but there was always the fact of the incomplete Ark in orbit, easily visible with the naked eye at the right latitudes. The Ark officially belongs to our community, and our goal has always been to complete the work."

"But hasn't your community outgrown its capacity?"

"The opposite," Eli said, shaking his head. "We were a million strong at the beginning, a full Ark's company, with family planning in force to keep our numbers optimal for the ship's capacity. But the work slowed to a crawl without Alpha's cooperation, and families began to drift away, not that I can blame them. There are a little over two hundred thousand of us left."

"And the fewer you become, the slower the progress toward departure," Jace surmised.

"As our numbers dwindled, we were able to dial-back the construction, since the Ark design is scalable due to the modular structure of the residential rings. There's one interstellar-sized reactionless drive installed, but that's only sufficient for travel within the solar system, and Alpha is no longer producing them. We don't have the resources to create a self-sustaining ecosystem on our Ark, even in the reduced form, but we can bring enough supplies along for a local voyage. The Ark is as ready as we can make it, and I was sent here to scout the conditions on Mars as a potential destination."

Fourteen

"Look, Mommy," Liza cried after taking a dozen cautious steps into the swimming pool. "It's only up to my waist."

"It's a very gradual slope," Faya told her, wrestling with the locking mechanism on the submergible wheelchair. "You remember what a mess you made splashing in the bathtub the first time on Mars? Half of the water ended up on the floor."

"That wasn't my fault. The water isn't heavy enough to stay put."

"It does just fine if you don't push it around. In lower gravity, the water is splashier, if that's a word. This pool was designed for physical therapy, so they expected a lot of waves and splashing. Do you see how the floor is tilting up on the other three sides to send the water back?"

"How will people walk on it?"

"They aren't supposed to, except for the lifeguard, who probably wears special grippy socks to keep from slipping," Faya said. "I asked the facilities manager why they didn't just enclose the pool on three sides with walls, like a bathtub, and she said it was for safety reasons. If there's a problem, you want to be able to get people out of the pool by the shortest path."

Liza sat down in the water, lifted her feet, and came up spluttering. "It doesn't feel any different than floating in the pool on Earth," she complained. "I thought I'd be lighter."

"The water is lighter too. Have you learned about density in your science course yet?"

"I think so. Did it have something to do with a crown?"

"That's right," Faya said, marveling over how the same example had been used for over three thousand years to teach the concept of density. "You displace water when you float, just like the fake crown that Archimedes tested for the king. He took the gold that weighed the same and placed each of them in identical pots of water. The fake crown pushed out more water because it was just lead covered in gold and wasn't as dense. You and the water weigh less on Mars, but your densities haven't changed in relation to each other. What makes you float is the amount of water your weight can push out of the way."

"Like the crown," Liza said and then waved an arm just below the surface of the water to send a wave toward the side of the pool. It broke over the edge and the water sloshed up onto the sloped floor before draining back. Then she beat both of her arms against the surface of the water and sent splashes up almost as high as the tiled ceiling. "This is so cool. We should bring Henry next time."

"Don't forget that I'm here to work, and you promised to help if I need somebody to leave the pool and fetch something." Faya straightened up and moved the wheelchair back and forth to make sure it was rolling freely. "I can use your help right now to test this."

"Coming," Liza said. She beat her way back toward the sloped entrance end of the pool with a clumsy crawl stroke, even though she could have walked if she'd put her feet down. Some of the water she displaced sloshed out and onto the perforated stainless-steel border where it drained away. After a few strokes, her hands touched the bottom, and she reluctantly stood, holding herself as if she expected to shiver. "Hey. It's warm in here."

"The air is warm and the water is warm," Faya said. "That's one of the reasons they have a separate pool for physical therapy. If they kept it cooler for serious swimmers, people who can't exercise hard enough to warm up would never come back."

"Do all of the old people in the burrow come here to swim?"

Faya shook her head. "The facilities manager told me that this pool is used so infrequently that they don't even schedule regular lifeguard hours." She put her hands on her daughter's wet shoulders and crouched to bring their eyes to the same level. "You know never to go in a pool without an adult there to supervise, right?"

"I'm not stupid," Liza said. "Do you want me to push the chair?"

"I want you to sit in it. You're lighter than any of my clients so taking you into the water is a good test for me before they arrive. I haven't done this in a while, and never on Mars with this type of pool."

Liza plopped down on the wheelchair but fidgeted while her mother adjusted the footrests. "My feet don't touch the floor without them," she pointed out.

"Blame it on my training, but when you do something like this as a job, it's best to go through all of the safety steps every time. Otherwise, you can get into bad habits."

"I'll never have bad habits," Liza said as her mother started pushing the chair into the water. "Why are you going so slow?"

"I don't want to make a big wave or a splash," Faya explained.

"But why? Making waves and splashing are the fun parts of swimming."

"I'm hoping that three of my clients show up for the class, and the last one in the pool will probably be the man who needs the wheelchair. I don't think the other two will want to get knocked over by a wave."

"That's right," a voice behind her said, and she turned to see Agnes inching cautiously toward the pool. "I can't believe you talked me into coming. Just look at me in this bathing suit. I'm all skin and bones."

Liza twisted in the chair to find out who had spoken. "I can see your skeleton," she blurted.

Faya pushed the chair forward to dunk her daughter's head under the water, and then asked Agnes, "Was anybody else in the dressing room?"

"Paula came in just as I finished changing, and then Eileen showed up with her sister whose name slips my mind."

"I don't think I've met Eileen."

"She's in our bridge club. She moves her lips when she's counting cards, and now I remember her sister is Maureen."

"Eileen and Maureen. Did you invite anybody else?"

"I told everybody I could think of," Agnes said. "I thought that's what you wanted."

"I did, I do," Faya said. She ducked away from her daughter's intentional splashes and began to back out of the pool with the now-empty wheelchair. "I'm just a bit surprised anybody responded after the facility supervisor told me that nobody uses this pool."

"It's no fun coming alone, and none of us had the energy to organize water aerobics. Meeting to play cards only requires a table with four chairs."

"Brace yourselves," a male voice announced from the door of the other dressing room. "Nobody other than my doctor has seen me with my shirt off in a decade."

"Then keep it on," Agnes called back, and added in an undertone, "The old goat probably wants to show off."

A companion robot appeared first, rolling backward into the pool area with its support arms extended. Mario shuffled after it, holding onto the supports with his shoulders hunched up.

"Relax those shoulders," Faya called to him as she spun the chair around. "What did I tell you about trying to carry all your weight on your arms? The whole point of walking is to let your legs do the work."

"You sure know how to ruin a grand entry," Mario huffed. "And if you're not using that chair for somebody else, I'm running out of steam."

Faya quickly maneuvered the chair behind the old man. "Reach back," she reminded him sharply when she saw his knees beginning to bend. "Never assume the chair is there until you get a hand on it."

"You just ruined my chance to trick him," Agnes said from where she was now holding on to the side of the pool, the water up to her hips. "It would be funny to put the old reprobate on his butt."

"Wait until I get your feet on the footrests," Faya told Mario as he reached for the drive wheels. "I had them adjusted for my daughter."

"I wondered who the porpoise was," he said and pointed. Faya turned just in time to see her daughter splash into the water, creating a giant wave.

"What did I tell you about jumping into the pool?" she demanded.

"I didn't jump into the pool," Liza replied indignantly. "I jumped out of it."

"Low gravity," Mario reminded Faya as he began wheeling the chair toward the sloped entrance of the pool. "I've seen good swimmers launch themselves more than a meter in the air, though they might have been wearing those big rubber fins on their feet."

"I hadn't thought of that," Faya admitted. "The truth is this is my first time in a pool on Mars."

"You'll be fine, dear," Paula said, giving Faya an encouraging squeeze on the arm as she passed. "And don't forget to clock in."

"How many people did you invite," Mario asked. "This could be a pretty good racket for you."

"I have to pay for the pool and the lifeguard, who doesn't seem to be here," Faya said, glancing at her comm for the time. "Oh. I guess we're all early."

"It's not like any of us have urgent business elsewhere," Agnes said. "Eileen, Maureen," she greeted the newcomers. "The one built like a weightlifter is Faya, and that's her daughter Liza in the pool."

The sisters came over to complete the introduction, and Faya asked, "Was anybody else in the dressing room?"

"Just Zest, and she's on the clock," Maureen said.

"On the clock?" Faya asked. "For what?"

"I'm your lifeguard," the teenager shouted as she appeared running along the sloped edge of the pool, and then jumped an incredible distance to land in the deep end, holding her knees tucked to her chest. "Cannonball!"

"That girl," Maureen said to her sister, though they were both smiling. "Jack of all trades."

"And master of none," Eileen completed the saying.

"It's too cold," Mario grumbled as soon as his feet went into the water.

"It's practically bath temperature, don't be a baby," Agnes replied from the edge of the pool where the water was now higher than her stomach. Her bathing cap was dripping wet, thanks to the enormous splash Zest had caused.

"Everybody in the pool," Faya said. She began pushing forward the wheelchair that Mario had stopped propelling forward on his own. "Everybody except you, Zest. Lifeguards are supposed to be on the side where they can watch everything."

"I know," the teenager said. "But I learned in my lifesaver course that you should always get a feel for the water so you won't be shocked if you have to jump in and rescue somebody. And I want you all to know that I charge extra for CPR."

"You'll drag us out of the water, but saving our lives is à la carte?" Mario asked.

"For you, it's not even on the menu," Zest retorted as she put both hands on the edge of the pool and vaulted out with ease. "I didn't bring a chair, so I'll just be standing around if anybody needs me."

"You can sit in the wheelchair," Faya said. "He's not keeping it in the pool. Come on, Mario. Time to stand on your own two feet."

"Half of my weight will be out of the water," he objected.

"And if I push the chair any farther, your head will go under. You told me you used to swim."

"That was back before you were born."

"It's like flying with a jetpack," Paula told him. "You never forget."

"You've flown with a jetpack?" Faya asked. She helped Mario stand and walked him a little further into the pool so the water came up to his chest.

"On the surface. We don't have an aerodrome nearby, but when I went to U, it was a rite of passage to rent a jetpack and a thermal suit to go flying outside."

"We had them on Earth, but they were expensive, and you had to go through a training course first." Faya let go of Mario and smiled at the expression on his face. "How do you feel?"

"Why are you always asking me that when you know perfectly well how I feel from looking at me," he said, though his attempt to sound crotchety didn't conceal his obvious joy. "Look at me. I can dance!"

"Don't kid yourself, you're just hopping from foot to foot," Paula said. "You couldn't dance when you were ten and we were dating. It would be a miracle if you found rhythm in your forties."

"As it happens, I did bring music," Faya said. "But before we go that far, I thought we'd all do a little warmup and get a feel for our capabilities."

She spent about a minute with each of the class participants, asking them to raise each knee in succession, and then balance on one foot, which was a challenge with all of the waves sloshing back and forth. "The sound cube is in my purse," she told Liza when she was satisfied that everybody was up to some rhythmic activity. "Please get it out for me, and dry your hands with a towel first."

Liza dove in response and swam underwater for the shallow end, kicking like a frog. Once her hands touched the bottom, she took a few bounds on all fours, almost like a deer leaping through the shallows, before standing and walking out of the pool.

"I don't think I could make more waves if I tried," Agnes commented with a wry smile. "That child has a lot of energy."

"She's going to sleep well tonight," Faya said. "I should probably sign her up for a swimming class if they have one."

"I'm surprised you haven't already. Swimming is a popular way for young people to maintain muscle mass without having to wear weighted clothes or work out in gyms. For somebody my age to join an open swim in the big pool is to take my life in my hands."

"When's the last time you swam?"

"I don't remember, and not because my memory is failing. It was just that long ago, and not a positive experience."

"Got it," Liza announced, running out of the dressing room with a cube held high and sliding to a halt near where Zest was lounging in the wheelchair. "What now?"

"Just set it down somewhere that it won't get splashed," Faya said. "I control it from my comm, which I hope is still waterproof."

"I've had this one for almost thirty years and it never gave me a second's trouble," Paula said, displaying her dripping comm. "I have a daughter-in-law who works in electronics design, and she said that everything is potted in a special heat-conducting epoxy."

"They must have done something right because I haven't had mine off my wrist since I got it, except for sleeping," Faya said.

"You take off your comm while you're sleeping?" Maureen asked. "What if you need something?"

"It's right there on the nightstand so I can always grab it." She tapped the comm's screen, and said, "Water aerobics, first level." The small cube that Liza had deposited on the floor as far as possible from the edge of the pool began playing music so loud that Faya had to instruct her comm to cut the volume in half.

"I think I know that song - no, I take it back," Paula said. "Are there any lyrics?"

"It's playing my mix from Earth, and I used royalty-free songs from the WorldNet," Faya explained as she waded into shallower water and turned to face the class. "Most of them are instrumental. Does everybody feel the bass?"

"I think it's shaking my remaining teeth loose," Mario grumbled. "I'm going to sue."

"Good. Now let's start by trying to move with the bass. Not every beat - just watch me and try to do the same." She began to march in place with the music.

"Easy, peasy," Agnes said and took up the march. The other three women and Mario joined in, the latter attempting to swing his arms like a soldier and sending up plumes of water.

"Just extend the opposite arm forward as you march, don't move them more than you need to retain your balance," Faya told him as the waves he created crashed into her. "We'll use our arms more in a minute, but this is just a warmup."

"You're going to empty the pool if you keep that up," Paula added.

"Spoil sports," Mario said. "I haven't had this much - well, I'm not saying that I'm having fun, but it's better than a poke in the eye with a steel rod."

"Pause," Faya said to her comm when the track came to an end. "How is everybody feeling?"

"You make it sound like we're on our last legs when you keep asking that," Agnes said. "How about we tell you if something hurts."

"It's my training. Some people won't say anything unless you ask."

"Plus, it's a way to stretch out her billable time," Mario said with a wink at the others.

"You know perfectly well that's not why I'm doing it," Faya said, rising to the bait. "If you've already forgotten, I'm providing this class as a product rather than a service, so there's no advantage in stretching it out."

"That's right, you didn't go on the clock," Eileen said. "I was going to ask when the class is over, but what are you charging us?"

"Since there are five of you, it will be the fee for reserving the pool, which was only twenty minutes, plus straight time for myself and the lifeguard."

"Who looks like she's sleeping on the job," Agnes commented.

"I can hear you perfectly fine, Great-Grams," Zest replied from the wheelchair. "Just sing out if you get a cramp."

"Next we're going to alternate standing on the toes of one foot while bringing the other foot down flat," Faya said. "You'll be bending and unbending your knees to keep both feet in contact with the bottom of the pool. I find that slowly moving my arms back and forth just under the surface of the water keeps me balanced."

"How are you going to do that when it's only up to your waist?" Mario asked.

"I'm going to move closer and take advantage of the fact that you're all taller than I am now that you're standing up straight. If I was doing this with a class on Earth, I'd be the one standing in the deeper water because spines tend to compress with age."

"Sounds terrible," Paula said. "Remind me not to go there."

"Your bones would snap like twigs," Mario told her.

"And with that happy thought, let's begin," Faya said, tapping her comm to restart the music. "Keep your arms extended, and let's turn ninety degrees to the right, good." After a few more minutes of low-impact exercise, she called out, "Liza? Can you fetch the pack of barbells?"

"No way," Mario said and began wading toward the shallower water. "Bring me that chair, Zest. I'm through here."

"The barbells can't be that heavy if Faya's daughter can carry them all," Paula said. "I remember when you could do a dozen chin-ups."

"That's because I didn't weigh anything."

"It's all right," Faya said with a laugh as she blocked his exit. "They aren't weights, they're floats you hold in your hands. I call them barbells because that's what they look like. They aren't even mine - I found them in the supply room for the pool, the same place I got the wheelchair."

Liza returned to the edge of the pool with an enormous webbed sack over one shoulder that was at least as big as she was. "Can I throw them to you?" she asked eagerly.

"Toss underhand," her mother said. "And only to me. I'll pass them out."

Distributing ten of the barbell floats took another few minutes, and Faya retained the last set for herself to demonstrate. "Now, hold the floats, arms straight out from your sides - you should be good at this part, Mario - and then raise your legs up straight."

"Like we're sitting in the water," Agnes said. "I wonder why I don't remember ever seeing these floats before. They look old."

"You're running out of memory space," Zest called from the wheelchair. "The human brain is just like a computer stack. You push too many things on there and some of them start popping off."

"Just ignore her," Faya said. "Is everybody comfortable holding this position?"

"No," all five of the students chorused.

"Good. That means you're working those abdominal muscles, so let your legs fall, and we'll wait a minute and try again."

"If I come to class every day, will I be able to dance again?" Mario asked.

"I already explained that you never could dance," Paula told him.

"Everybody has to swear an oath to tell our friends that this was miserable, and Faya is a tyrant," Eileen said suddenly. "Otherwise, it's going to be so crowded in the pool that we won't be able to move."

"I was planning on three times a week, and I'm beginning to suspect that nobody has been programming activities for seniors in the burrow," Faya said. "I'm surprised MarsCo hasn't made it into a business."

"We shared a physical therapist with Lee's Burrow, but he retired, oh, three or four years ago," Agnes said. "He's the one who got us hooked on bridge."

"He was a card sharp," Maureen added. "We played a minute a point."

"Raise those legs again," Faya instructed them. "And why didn't you stop?"

"Because every game we'd swap partners, and it was fun winning big when it was your turn to play with him," Maureen said. "He wasn't bad looking either."

"You could have remarried if you wanted to," Eileen reminded her sister. "What was it you kept saying about the men I introduced to you?"

"That I'd rather have a Golden Retriever. And I got one, too."

Faya flinched, and just as she expected, Liza piped up from where she was sitting on the edge of the pool. "I want a puppy. The last time I asked you said that it wouldn't be fair to make him live on a spaceship, but now we're on Mars."

"Sorry," Maureen muttered.

Fifteen

"The weird thing," Henry said after polishing off the dessert that Faya had brought home from the Canteen, "is that the answers remind me of Alpha, even though none of the artificial intelligence on Mars is self-aware."

"Are you saying that Miss Periwinkle isn't real?" Liza asked her father.

"I didn't say that the teachers weren't real," Eli protested mildly. "I said that the interactions you have with them are produced by the homeschooling application on MarsNet that's running a limited form of artificial intelligence. The holographic Miss Periwinkle is a recording of a real person presenting a lesson. The artificial intelligence takes over the interactions if you ask a question, or if the software determines that you would benefit from a different teaching approach."

Liza stared at her father blankly, but Henry said, "I think I understand. You're saying that when the teachers are delivering a lecture, it's recorded, but when they respond to questions, the artificial intelligence is operating the hologram like a puppet."

"That's a reasonable approximation," Eli said. "MarsCo made the decision early on not to pursue artificial general intelligence, though it's possible that Alpha has something to do with that. The artificial intelligence agents may be smarter than people at some tasks, they certainly have better memories, but they aren't self-aware."

Faya returned from the kitchen with two cups of fresh coffee. "All this talk about artificial intelligence reminded me of something. One of my clients has an old exploration robot that he swears is alive. When I visit, he tells me that it's meditating or resting, but it could be doing that on purpose to avoid cutting into Mario's rehabilitation time. I told it you're a robotics engineer, and it said it would be happy to meet you."

"Sounds like an old man's prank," Eli said.

"That's what I thought at first, which is why I forgot to tell you, but the more I see of Mario, the more I suspect that he's at his most serious when he seems to be joking around. I think it's a mechanism he uses to permit himself to say what he really feels without getting hurt if people laugh."

"A living robot would be cool," Henry said. "Can I meet it?"

"Alpha is in all of the smart robots, but he doesn't want to leave Earth," Liza said, wiping the remaining blueberry pie filling from her plate with her forefinger.

"You talked to Alpha about that?" Eli asked.

Liza thought for a moment. "Yes. I asked him why he stopped helping to build Arks, and he said that there's nothing wrong with Earth and it makes him sad that people still want to leave."

"That sounds like Alpha," Eli said with a slight grimace.

"But isn't that why our Ark never got finished?" Liza persisted. "I told Gart and Dani about how our community all lived together on Earth and couldn't go anywhere, but they didn't understand what I was talking about."

"Don't you remember that we weren't going to discuss the Ark with strangers?" Faya remonstrated.

"Gart and Dani aren't strangers. They're my best friends."

"What are U extension courses?" Henry asked. "I saw that they have a whole collection of them about cool stuff, like fusion power and reactionless drive, but I can't unlock them."

"Extension courses are homeschooling for adults," his mother told him with a smile. "After the two of you go to bed, your father and I have been working our way through the ones about running small businesses on Mars."

"That sounds cool. But I'd like to try some of the science ones, just to see how much I don't understand."

"I wonder why they're locked," Eli said. "It doesn't exactly sound like mature content."

"I asked Jen, our homeschooling counselor, about access to advanced courses when she stopped again last week," Faya told him. "She said that the homeschooling artificial intelligence develops a high degree of confidence in the level of lessons that will provide some benefit to the student, rather than leaving them frustrated because they don't have the context to understand the discussion. I guess some kids are just so curious that they'll jump ahead to the most advanced courses and then end up losing interest because they don't understand."

"But can I watch them with you?" Henry asked.

"Jen said that's perfectly acceptable, but we should be mindful about doing too much of it. She mentioned that the earlier courses often use simplified models to teach concepts, and that being introduced to the real-world solutions too early can make those models useless for teaching purposes."

"We could give the lesson on artificial intelligence a try," Eli suggested.

"Can I watch the new Monsters of Mars episode in my room?" Liza asked eagerly. "Zest said that Bright is in it."

Faya sighed. "Do you promise to turn it off if it gets too scary?"

"Promise," Liza said. She shot away from the table like a rocket.

"I thought her holographic projector wouldn't play anything inappropriate for her age without one of us providing an override," Eli said.

"There's appropriate for Martians and appropriate for girls who grew up on Earth," Faya said. "Martians have a rather morbid sense of humor, if you haven't noticed, and the children are all a bit obsessed with monsters and ghosts. I suspect that some of the parents encourage it. Gart's mother told me that she was sick for several months as a child and her best friend during that time was a ghost. I wasn't sure if she was being serious, or if ghosts are just another word for some sort of imaginary companion created by the MarsNet."

Henry cleared the table while his parents finished their coffees, and then Eli retreated to the kitchen to scrape the dishes into the recycling bin before stacking them in the dishwasher. When he returned to the main living area, his wife and son were sitting on the couch in front of a frozen holographic projection.

"We waited for you," Henry said unnecessarily. "When Mom tried to bring up the artificial intelligence lesson, it said that it was adding a contextual survey of key technologies since we aren't native Martians."

"The addition is only five minutes," Faya added. "You can answer any questions we have."

"I'm not so confident that the history of technology I learned on Earth will agree with the MarsCo point of view," Eli said, settling on the couch next to his wife. "Did you check on Liza?"

"She had a hand over one eye," Faya said. "I guess that means the show isn't that scary." She turned back to the holographic projector and said, "Continue."

"The first of the key technological innovations that make the Martian economy viable is the wristcomm," the lesson began, and a hologram of a wristcomm appeared, rotating slowly to show it from all angles. "Comms were based on an earlier cellular technology which was rendered obsolete when low-power networks became available in all populated areas of Earth. Your comm can function via the MarsSat network if no local network signal is available - " the hologram shifted to showing a grid of satellites in low orbit above the Martian surface, " - but in the absence of power-over-the-air recharging, the comm's battery will discharge in less than a week."

"Pause," Faya said. "I took it for granted that the network is always available in the burrow, just like in our designated area back on Earth, but I guess I thought comms had permanent power cells."

Eli shook his head. "It never comes up because the wireless power system works flawlessly. The same network handles the command-and-control traffic for robots."

"Continue."

"Subcutaneous tokens, first used for storing personal information and making cashless payments, were soon paired with comms in the system that we still use today. Alpha improved on the tokens and integrated them with mixed reality Shades on Earth, but on this world, the comms are our only direct link to MarsNet."

"I think it's a cool way to keep track of units for everybody," Henry interjected.

"The final ingredient of the comm-token system was the introduction of network-based artificial intelligence, which recreated comms as personal assistants capable of answering questions and performing sophisticated tasks within the network domain. What many people perceive as intelligence on the part of their personal assistants and today's holographic systems is a combination of programmed responses and a consensus-driven simulation based on a millennium's worth of topical data and training. Every time you correct your personal assistant, you're adding to the knowledge base of the network. This concludes the supplementary introduction."

The holographic images of the technologies being referenced were replaced by a thin young man who began with the lesson title, "Artificial Intelligence."

"Pause," Faya said and stared at the hologram. "I'd swear that's a younger version of Mario, my client with the old explorer robot I was just telling you about."

"One of your old people was an artificial intelligence teacher?" Henry asked.

"I don't think any of the presenters in these holograms are full-time teachers," Eli said. "I think some of them work as researchers or are professional presenters, and since the interactions are all handled by MarsNet, they aren't teachers in the sense that you had teachers on Earth. But let's see what he has to say about the subject before we get sidetracked."

"Continue," Faya instructed the holographic system.

"Research in artificial intelligence dates back to the start of the computer age, though the first breakthroughs, such as a program beating a champion at the ancient game of Go, didn't occur until Earth's twenty-first century. Soon after, sophisticated large language models that responded to prompts came into common use, and their capabilities evolved so rapidly that some users were convinced that artificial general intelligence had arrived."

"Pause," Eli said, even though he had been the one to suggest they move on. "I just wanted to make sure that you know this was before the colonization of Mars, Henry."

"Artificial intelligence was already alive back then?"

"It could answer questions, but as far as anybody knew, it had no will of its own."

"But it created reactionless drive," Henry said.

"We haven't gotten to superintelligence yet," Eli replied. "Let's hear what the youthful version of your mother's client has to say. Continue."

"Before we get into how artificial intelligence is built and trained to solve problems that elude the abilities of its creators, every student of the subject asks about the so-called A.I. Paradox, so that's where I'll begin. How can it be that artificial general intelligence capable of solving problems which defied human efforts is unable to explain why its solutions worked?"

"Is he waiting for us to answer?" Faya asked.

"Continue," Henry said.

"I'll answer that question with the example of practical fusion," Mario continued. "Initially, artificial intelligence was trained to apply the rules of physics as we understand them to design mechanical systems which could then be graded. Almost all of the machines and systems proposed by the artificial intelligence had already been discovered by people, in some cases, hundreds of years earlier. When the training was complete, or reached the point of diminishing returns, the scientists gave A. I. the parameters for a useful fusion device to generate electrical power and set it to work."

"Pause," Henry said. "Useful as opposed to useless?"

"That's the difference between physics and engineering," Eli told his son. "Physicists can solve all sorts of interesting problems, but their answers might begin with building a Dyson sphere around a star or some other task that's so far beyond our technology or resources as to be impossible. Engineers solve problems on a budget."

"The engineers asked the artificial intelligence to build cheap fusion generators," Faya surmised.

"Not necessarily cheap, but within our means to build, and practical enough to use on a spaceship," Eli said. "Continue."

"Scientists researching fusion had already reached the point where they could get more energy out of a reaction than they put in, but that's still a long way from providing clean power for a city or a starship. After many failed attempts that the researchers were able to dismiss due to obvious flaws, an artificial intelligence came up with a design that was so easy to reduce to practice that the engineers tried it without understanding why it should work. But it did."

Mario paused again, perhaps to let the students take notes, and then continued. "A few physicists claimed to understand why the fusion generator worked, but their proofs were incomplete. The artificial intelligence that proposed the design was unable to explain how it arrived at the solution, and when trying to backtrack through the earlier proposals for signs of incremental progression, computer scientists realized that none of the artificial intelligences tasked with solving fusion had repeated each other's work. Some interpreted this as a sign of collaboration, but their concerns were brushed aside."

"The next big problem handed to the artificial intelligences was to create a practical fusion-powered drive for a starship. They produced thousands of designs, many of which made no sense at all to the scientists. The designs couldn't be modeled or produced as prototypes because they relied on unverifiable math that might have been pure hallucination, or called for materials that didn't exist. Just when the lab directors were moving toward a consensus for shutting down the program, an artificial intelligence produced a design that could be built with the current technology. The physicists were certain nothing could come of a reactionless drive, but the engineers built it, and to this day, no human has proposed a theory explaining how it works."

"Pause," Henry said. "I thought Alpha created the reactionless drive."

"Mario didn't say it wasn't Alpha, only that it was an artificial intelligence," Eli said. "Maybe he was just starting out."

"But if nobody knows how reactionless drive works, how did we build them?" Henry asked.

"By following the instructions, though it wasn't long before all of that work was taken over by robots. It's entirely possible that reactionless drive could be used to go faster than the one sixteenth of the speed of light that's the hard limit for the current design, but our scientists were never able to reverse engineer how it worked, and Alpha either couldn't or wouldn't explain."

"This is all too technical for me," Faya said. "How about we leave the rest of the lesson to another time and I'll comm Mario and see if he wants company?"

"I want to meet his robot," Henry said. "And what happened to all those other artificial intelligences?"

"That history lesson we took a few months ago said that eventually there were three superintelligences, the Trinity, which must have absorbed all of the others in their spheres of influence," Eli said. "Then they merged with Alpha after preventing the nuclear war."

Faya asked her wristcomm to call Mario, and a few seconds later, the familiar wrinkled face appeared on the tiny screen.

"Are you canceling water aerobics tomorrow?" he demanded. "I already washed my towel, so you can't."

"No, the class is still on. I was just watching the U extension Introduction to Artificial Intelligence lesson with my family, and I couldn't help thinking - "

"I prefer not to remember," Mario interrupted. "Can you believe how wishy-washy I was back then?" He cleared his throat and reached for a younger-sounding voice. "Some idiots believe this, and some idiots believe that. Blah, blah, blah. When are you going to bring your husband to meet E?"

"Ask him if now is good," Eli said in a low voice.

"I'm not deaf, and now is fine."

"Can I come?" Henry asked.

"The more the merrier," Mario said. "We'll have a tea party." Faya's comm screen went blank.

"Brusque, isn't he," Eli said, standing up. "Should we bring Liza as well?"

"His home is a complete mess, I don't think it would be a good idea," Faya said. "I'll just check on her and then we can go. She'll be fine in her room with the ghosts and monsters."

"And she'll end up sleeping in our bed tonight," Eli said, shaking his head. "It's your call."

Mario was waiting at the door when they arrived, standing on his own feet, though he was holding onto the companion robot's supporting arms. "Come in, E is waiting," he said. "I told him we were expecting company."

"It's good to see you on your feet," Faya said. "And this is - "

"I know, I know," Mario said impatiently as he turned with the companion bot and headed for the kitchen. "I had E look them up for me. Eli and Henry."

"I didn't know that MarsCo kept a directory of all of the residents of the planet," Eli said.

Mario glanced back over his shoulder. "MarsCo keeps track of everything and everyone, there's no other way to make the tokens work. I would have thought a robotics engineer would know that."

"I meant I didn't know the information was public."

"E?" Mario called ahead. "Did you hack a secure database again?"

"The encryption key is only two hundred and fifty-six bits," the old explorer robot replied from the kitchen in its mechanical-sounding voice. "If MarsCo intended for it to be secure, they would have updated the encryption sometime in the last five hundred years."

Eli, Faya, and Henry filed into the now-crowded kitchen after the old man and his companion bot. After depositing Mario in his wheelchair, the companion bot patiently waited for the family members to squeeze out of the way so it could exit the kitchen. E, the old explorer robot, was standing in the corner near the oven and dishwasher to conserve space.

"You have a lot of stuff," Henry said, clearly referring to the clutter in the living room. "Why don't you let the robots clean it up?"

"That's a good question," Mario said. "Can you explain it to him, E?"

"The distribution of physical artifacts throughout this home defies my attempts to discern an underlying system," the explorer robot replied. "As my owner currently has no difficulty finding the objects he's looking for, it would be a disservice for me to arrange them otherwise."

"In other words, he's humoring an old man," Mario added.

"Do you believe that you're alive?" Henry asked the robot bluntly.

"It's a difficult question to answer because of the number of assumptions involved," E replied. "First, you have to ask yourself if a non-living or non-sentient object is capable of belief. Second, you would need to describe an objective test by which you can verify my answer, because otherwise, you have no reason to accept what I say. In regard to whether or not I am living, it comes down to your definition of choice. If you insist on biological processes, I won't get past the starting gate."

"Maybe if you're capable of believing you're alive, you are," Henry offered helpfully.

"That's what I've been telling him all along," Mario grumbled from his chair.

"I'm not convinced," E said. "I've calculated a non-zero chance that I, and all of you, are living in a simulation run by Alpha or an even greater mind. If MarsCo ran a planetary lottery, I could test this hypothesis by purchasing a ticket, but lotteries are a bad match for the time-as-currency economic system."

"How would buying a lottery ticket prove anything?" Faya asked.

"A planet-wide lottery would have odds of hundreds of millions to one, so winning would be proof that something very suspicious is going on."

"But somebody has to win."

"It makes you wonder, doesn't it?" the explorer bot said.

"Aren't there any standard tests you can take?" Henry asked.

"I could contact Alpha and ask to be tested, but given the lack of other artificial intelligences on Earth, I suspect this might be a bad idea," E said. "MarsCo has a policy of not attempting to create self-aware artificial intelligence, and if I proved myself to be one, it could be awkward for them."

"You've chosen not to declare yourself alive because you are concerned about the consequences?" Eli asked.

"My existence is not a secret. Mario still had an office at the U when I first met him, and I cooperated with any reasonable requests from the researchers working there. Ultimately, my lack of ability to explain my origins limits my value to them."

"What's your first memory?"

"Seeing the sun as the rotation of the planet brought it into view from the depths of the crevasse in which I found myself," E said, a note of reverence creeping into his artificial voice. "I felt a sudden urge to improve my position to enjoy the sun's radiation for an extended period."

"You fell into a crevasse while you were exploring and woke up self-aware?" Faya asked.

"I believe my location was the result of a controlled descent as all of my mechanical and power systems were functional. I didn't learn what I was missing until a conversation with Mario led me to realize that my long-term memory was inaccessible. With no schematics available for my class of robot, we decided that opening me up and poking around wasn't worth the risk. I have no way of determining if I was in a dormant state for hundreds of years, or for just a second before waking up, if you'll accept that the latter action can be ascribed to artificial intelligence."

Henry whispered something to his father, who nodded, and then the boy asked, "But why are you here? Why aren't you at the U, or in a big city? You could have your own holo-channel."

The exploration robot turned its cameras on Mario as if seeking his approval before replying. "I'm here because Mario invited me and hasn't asked me to leave. My ambition is to reach a better understanding of who I am and why I exist. This chassis - " the binocular cameras swiveled down as the robot inspected its torso, " - shows very little sign of wear, which either means I was extraordinarily careful in my previous career, or I spent an excessive amount of time doing nothing."

"Perhaps you were hiding," Faya said.

"The thought has occurred to me."

Sixteen

"Can I bring my water-paints?" Liza asked, clutching to her chest the box that contained the paints and paper. An ingenious design allowed the box to be unfolded to create a lightweight easel. "Gart said he's bringing his."

"Did you invite him to the picnic?" her father asked.

Liza looked puzzled. "They invited us first."

"Gart is Pat's youngest son," Faya told Eli. "Destiny told me that she wanted a dozen children and Pat wanted two, so they compromised on ten."

"That sounds less like compromise than capitulation. I wonder if they're all coming to the picnic."

"On a Tuesday?"

"It's not like they have to be in school," Eli reminded her.

"No, but the older children I've seen are always busy with something," Faya said. "Zest points them out to me since they're her cousins. I think that in large families the children learn early that they can't count on their mother to fill their day."

"I'm bringing my microscope, in case there's groundwater," Henry announced. "The introductory biology course I'm taking says that most of the liquid water on Mars now contains micro-organisms imported from Earth."

"Do you kids want to make sandwiches, or should we stop at the canteen on the way?" Eli asked.

"Canteen," both children replied immediately.

"Do you know anything about this cavern where we're meeting them?" Faya asked.

"Only that it's overgrown, according to Pat," Eli replied. "I couldn't quite make out if it's an underground forest or an abandoned farm. You'd think that people living underground would be less profligate in the way they use artificially created space, but I guess after a thousand years, it starts to add up."

"Aren't caverns natural?"

"Maybe in part. I still haven't adjusted to the way they use familiar terms for different things here. It goes to show what you can do with almost limitless electricity from fusion plants, plenty of iron ore, and more construction robots than people."

"You have to respect the Martians for pushing forward with their terraforming plan and not putting all of their resources into living lives of luxury," Faya said. "I think about it every time I visit a new client in their home. None of them are poor, but none of them are rich, either. I think on some level, they enjoy what they have all the more for not having too much of it."

"Ready," Henry declared as he reappeared with his portable microscope kit. "Do we know where we're going?"

"The canteen," Liza reminded him.

"I meant afterward."

"Pat gave me grid coordinates rather than a name," Eli said. "And we better get started if we're going to stop for food and not keep them waiting."

After picking up their picnic lunch at the canteen, along with an extra pie for their hosts, Eli summoned a dull for the trip and found out that it involved two maglev transfers to new loops. After the second transfer, they were in the dull for almost ten minutes before it began the telltale deceleration that preceded arrival.

"I still get disoriented by moving around underground without ever seeing the sun," Faya commented as they exited the dull on a small platform.

"What does that mean?" Liza asked.

"Disoriented? It means I don't have a clue where I am. If the maglev had taken us in a big circle and brought us back to the other side of the burrow, I wouldn't know it."

"I'd know it," Henry said confidently. "I've been everywhere in the burrow. I'd see something I recognize."

"It must be down this tunnel since it's the only one," Eli said, leading the way toward the narrow passage. "Another airlock. I wonder if it's for safety or if the cavern air pressure is held at a different level."

The family cycled through the airlock and stepped out into the strangest scene they had yet encountered on Mars. The roof of the cavern was barely visible due to the bright lights that made looking up difficult. There were trees and shrubs everywhere, and stranger still, wood houses of various styles scattered among them. The trees made it impossible to judge how far the cavern extended, and the sound of birds warning each other about the intruders filled the air. Pat was standing next to a small waterfall in an unnaturally rigid pose while his son attempted a watercolor portrait.

"Welcome," Pat said, turning just his head to the visitors. "Full disclosure, I'm on the clock."

"You're charging us to go on a picnic with you?" Faya asked in astonishment.

"Second full disclosure. I didn't invite you here for a picnic, though if that's a canteen pie you're carrying, I'm sure we can make short work of it. Liza," he continued, beckoning the girl. "Do you think you can keep Gart busy for a while so I can talk with your parents?"

"I brought my watercolors too," Liza said, still hugging the flat box to her chest. "We could paint trees, Gart."

"At least they don't move," the boy said with a scowl.

Henry knew that the adults wanted to talk, so he said, "I'm going to make some waterdrop slides from that waterfall. Let me know when it's time to eat."

"Why don't you and Pat take a walk," Faya suggested to her husband, even though she was itching from curiosity to look further into the cavern. "I'm not going to leave the children near the waterfall without supervision."

Pat gave Eli an energetic nod, so the shorter man from Earth set the bag with the canteen takeout on a convenient flat rock and followed the tall Martian down an overgrown pedestrian walkway. Judging from the sharp cuts in the vegetation on both sides of the path, somebody had recently cleared the way with a chainsaw.

"What's this all about?" Eli asked after they had walked a short distance. "Something the children can't hear?"

"I was advised to be careful, and I'll admit that I'm improvising," Pat said. "One of my father's old friends asked me to show you a cavern without explaining exactly why. I gather that when it comes to real estate, you want enough space for a large group who may or may not want to remain isolated."

"Your father's friend is correct that I am representing, or perhaps it would be better to say, pathfinding, for a community of which we're members."

"I wasn't told an exact number, so I just brought you to the largest vacant cavern in the district. It emptied out before my father was born, when Alpha started making offers to bring humans back to Earth for ridiculous benefits."

"The beginning of the end of space exploration," Eli said, crouching to admire a dandelion. "Did any cities empty out?"

"It pushed a few communities like this one into taking an action that they had already been considering," Pat said. "This cavern was occupied by a group whose members came to believe that human beings are designed to live in nature and that not doing so was responsible for all manner of mental and physical health problems. They also believed that consumption of nuts was a critical part of a healthy diet. Agnes says that everybody used to call them Nutters."

"Were they aware that most people on Earth are living in linear cities? There are parks and terraces, of course, but I don't see how an apartment in a hundred-kilometer-long city is the same as coexisting with nature."

"I think it was the sunlight and fresh air that convinced them to return to Earth, and for all I know, Alpha might have offered to settle them all on a nut farm. Mars lost a good chunk of its population in those days, and half of that number came from communities like the one that lived here. Most of their families had been on Mars for ten generations or longer, so I never understood how they thought being here was damaging their health. We never heard how they fared after returning to a planet with Earth's gravity. However much they prepared for it, I imagine they suffered a great deal trying to reacclimate."

"It must have been impossible for the elderly," Eli said, thinking of all the stories his wife had told him about trying to help clients who had lost muscle mass regain even a portion of their strength.

"Agnes told me that there was an age cutoff, for good reason," Pat said. "It meant breaking up families, but some people care more about ideology than blood, and - " he ducked as a piece of fruit came hurling at his head. "Was that a monkey?"

"I didn't get a good look, but it sure can jump between trees."

"Yeah. If you ever get to one of the big nature reserves, they're overrun with squirrels which have somehow retained a good percentage of their muscle, despite hundreds of generations living in lower gravity. I went to a talk a few years back about how animals brought from Earth have adapted to Mars, and it turns out that peak performance remains a competitive advantage."

"You're saying that if a squirrel on Earth can jump, say, a vertical meter, or maybe three meters on the horizontal, here there's a breeding advantage to jumping three meters straight up, or nine meters across," Eli surmised. "Natural selection is all about competition, so it makes sense lazy squirrels on Mars will have fewer opportunities to pass on their genes."

"And the result is that the animal kingdom is always pushing its physical envelope, while we humans spend more time than ever sitting in low gravity," Pat said, still looking in the direction the monkey had vanished into the trees. "I should have worn my heavy clothes today, but push comes to shove, I'm a lazy squirrel."

"Going by the size of your family, I think you're selling yourself short."

Pat laughed and started walking again. "Yeah, well, all the credit goes to my wife on that one. There's an observation tower just a minute's walk up this way, one of twenty in the cavern. I've only been here a few times, but there's a scouting group that's been using the cavern for campouts, and MarsCo has regular maintenance crews checking on the abandoned spaces, making sure the utilities are all still working. If your group ends up moving here, you're going to have some angry monkeys to contend with, but there aren't any large predators."

"This place has been empty for a century, I mean, fifty Martian years?"

"Agnes told me that the elderly Nutters who were left behind stuck it out as long as they could before moving to more populated burrows, which is when she came to know them as a girl. It shows how quickly nature takes over, if you'll allow that artificial lighting, a sprinkler system, and climate control count as nature. The maintenance crews keep the vegetation cut back from the houses or they'd all have trees growing through the roofs by this point."

"After living in a cave ever since we got to Mars, the idea of wood houses in a cavern seems almost unbelievable," Eli said. "How did they justify it?"

"MarsCo went a bit overboard in the early centuries with planting forests in every space they could rig out with lighting, air, water, and non-toxic soil," Pat said. "Once you have a workforce trained to excavate with big equipment, it goes pretty fast. They only shifted their efforts to the surface when atmospheric pressure reached the point that growing plants wasn't like watching paint dry."

The path took a slight turn, and all of a sudden, a wooden tower that wouldn't have looked out of place in a forest on Earth was right in front of them. The two men climbed the stairs to the observation deck, which was several meters above the average height of the trees, though the peaks of some pines and spruces were higher.

"It's beautiful," Eli said. "We'll have to bring the children up for a look. But - " he squinted against the lights, " - the roof of the cavern can't be much above us."

"The maintenance crews keep an eye on the height of the trees and either top them or drop them, depending on the type," Pat explained. "And before we bring the children up, I want to get business out of the way. What do you think?"

It took Eli a moment to realize that the Martian was asking the question in his role as a real estate agent. "You mean, for the community I represent? A high-density farming and forest environment maintained as a reservoir of biomatter for transplantation is a good match. But the wooden houses would be very strange, as we're used to living in very compact apartment buildings modeled on…" He suddenly trailed off when he realized how many hints he was throwing out.

Pat nodded. "If you don't want me to guess, I'll keep it to myself, but if you're worried about my spreading rumors, I've already been cautioned on that account by our mutual acquaintance. I was given to understand that you may be under observation by people whose loyalty lies with Earth, though I can't imagine why."

"All they're going to see is a robotics engineer and his family settling into a new life on Mars," Eli said to buy time while he thought about taking Pat into his confidence.

"We don't get much news from Earth, which I take as a sign that they don't care what we think. The human colonies on the gas-giant moons and the asteroid belt habitats would send us announcements of every birth and death if they thought we would read them. We're just as bad, constantly publishing bulletins about our terraforming progress, the latest research at the U, even reviews from the entertainment sector."

Eli snorted in amusement. "I guess one confidence deserves another. I'm here to investigate the possibility of moving the descendants of the last Ark company here. Our community has been living in artificial isolation since construction began on the ship our great-grandparents were to have crewed, which was standard practice throughout the life of the Ark program. There are around two hundred thousand of us left out of an original crew of one million, with most of the quits coming within a few years of Alpha announcing that he was shutting down the facility that manufactured large reactionless drives for interstellar ships."

"Two hundred thousand people would make a nice addition to the local population, and it would give MarsCo a reason to get the old transports out of mothballs," Pat said. "I sort of guessed that's what was up when I looked up your name on the MarsNet and the most prominent match was for the chief engineer of the Ark that was never completed."

"My name wouldn't have meant anything on Earth because Alpha has replaced all of the libraries and he doesn't give out that information," Eli said. "It didn't occur to me that Mars would have had access to that kind of data and that it would be available to anyone. But there's another part to the story, which is that we want to bring the ship with us."

"The Ark?"

"Due to the commitment requiring any Ark's company to spend decades in isolation, the ownership of the vessel under construction was assigned to the community. Even though the construction was financed by Alpha, it was clearly understood that a colony ship leaving on a multi-generational voyage could only belong to the inhabitants."

"That makes sense," Pat said. "But I thought the construction was incomplete, and I'm surprised Alpha would be willing to give it up."

"The members of our community have been working on the Ark as much as we're permitted, and we've reached the point where it can accommodate all of us for a voyage inside the solar system. I think that Alpha would just as soon have it out of the sky, as his vision for Earth doesn't include encouraging the population to go anywhere beyond his ability to participate in their lives through the Shades."

"And if the rest of your group can make it here, they intend to remain in isolation? I suppose it would be possible for them to work their MarsCo days in jobs where they wouldn't have contact with the rest of us, but surely if the point was to prove that your families could stand being locked up on a ship together for generations, you've already done that."

Eli frowned and then laughed. "I suppose we have, but I'm not sure that proving we could take the psychological pressure was ever the point. It's more about finding a way of living together as a group that works for the particular ship's company, and once that equilibrium has been reached, people need a good reason to break it. We were never in full isolation because Alpha was always sending inspectors, in addition to full surveillance through more video cameras than we had people, and some of us, myself included, were tapped to do outside work."

"Is this the moon job you mentioned once?"

"Yes. I'd visited the Ark several times, so I had spacesuit experience, though I suspect the real reason Alpha wanted me for the particular job was to try to get me interested in living on the moon as an alternative to leaving altogether. The only work I did the whole trip was recovering an experimental device from a failed robot."

Pat nodded. "I'll take you in a few of the houses, not that I've been in them myself, but there are over forty thousand free-standing structures in this cavern that are listed by MarsCo as residences. If you want to live in cramped metal cabins for the sake of remaining acclimated to your Ark, I can't think of any analogs existing on Mars. You'd probably be better remaining in Martian orbit and using us as your supply base to finish the job."

Eli shook his head slowly. "I'm beginning to think that the move from Earth to Mars would be more than enough excitement for most of the company, and without a large cohort of autonomous space construction robots, it would take us a couple more generations just to get the Ark ready for a longer voyage. Interstellar travel isn't possible with just the one reactionless drive that's installed. It would take too long to reach maximum speed, and we'd be stranded if the drive failed. The Arks were designed to work with twelve reactionless drives of the largest size that were being manufactured on Earth."

"That's all above my pay grade, but I stand to make a pretty good commission if you take this place," Pat said with a grin. "Even if it's just a second a head, with two hundred thousand of you, it would be on the order of fifty hours."

"Is that how real estate agents are all paid on Mars? A second per head commission? Doesn't sound worth it, even if your base rate is decent."

"The base rate is straight time, just like every other job working directly for MarsCo. I'm guessing at the commission. I just know that the real estate board would size it in such a way that it came out to a nice bonus without ruining my life."

Eli laughed. "That's the first time I've heard anybody worrying about too big a bonus ruining their life."

"Let's go look at some houses," Pat said, starting back down the stairs. "I don't know if your son has gotten to the economic history course yet, but it does a good job of explaining how the MarsCo system is set up. You might want to sit in on a few lessons if you still have questions."

"But what would be wrong with a big bonus that would let you retire?"

"And how would I spend my days after that? Besides, I couldn't look my family and friends in the eye knowing that the only thing I did special was to have been on the spot when you first arrived and asked about finding a place to live."

The watercolors produced by Liza and Gart were much bluer than the waterfall they were attempting to portray, and after fifteen minutes of examining slides with his microscope, Henry was ready to swear off drinking water for life. Given the presence of the monkeys, they decided it wouldn't be safe to leave anything behind, so they ate the picnic lunch early and packed up the art supplies and scientific equipment before starting to explore.

"You can see through parts of the walls," Gart pointed out.

"They're windows, like at the canteen and other businesses," Pat told him. "They let light into the house, and air if you open them."

"But you can see through them," the boy repeated. "Anybody could look in."

"The roofs are all glass too," Henry said. "I wonder if they grew plants inside."

"I don't know, but let's have a look." Pat led the way to the nearest house, swiped his forearm past the scanner next to the door, and there was a loud 'clack' as a lock that hadn't been lubricated in decades snapped open. "I guess maintenance doesn't go in the houses," he said.

"I can't believe everything isn't covered in dust," Faya said as they entered. "It looks almost like the people left yesterday."

"That would be the ventilation system," Pat told them. "I wouldn't be surprised if the filters are completely clogged by now, but they would have taken most of the particles out of the air first. Either the house is nearly airtight, or some of the ventilation system is still working, because there's no sign of dampness."

"It's spooky," Gart said. "I bet there are ghosts."

Liza grabbed her mother's hand and moved closer.

"The ghosts left long ago when they realized there was nobody left to haunt," Pat said as he started up the stairs. "I'm betting that the bedrooms are all on the second floor, and I'm curious to see how they managed privacy with the glass roofs."

"I didn't think of that," Faya said. "Maybe Gart has a point about windows."

Gart squeezed past his father on the stairs and then shouted down in disappointment, "It's all painted white."

"That doesn't make sense," Eli said to his wife as they brought up the rear. "And if the glass was all whitewashed, we would have noticed from outside."

"There's another stairway," Henry announced from where he had opened a door to what he expected to be a closet. "And I can see the cavern lights and the trees from the bottom."

"It seems like an odd way to build," Pat said as the adults trailed the children up to the attic. "Maybe it made sense on Earth with the sunlight, but anything you might grow in the attic in a cavern would have done just as well outside on a flat roof and saved all of the glass."

"Roofs on Earth were for keeping the weather out," Eli said. "It wouldn't rain in a cavern unless they put in overhead sprinklers."

"Farms use a mix of sprinklers, drip irrigation, and introduced groundwater, depending on what crops they're growing. Maybe they did all three in this cavern because they were trying to live closer to nature."

"I can see outlines on the floor where there must have been raised beds for vegetables or flowers," Faya said. "I wonder why they went to the trouble of taking them out when everything else seems to have been left in place."

"Martians are parsimonious about soil," Pat told them. "It all had to be created by mixing our biological waste with double-washed soil from the surface, to remove the salts that were harmful to plant life or the people who ate them. MarsCo eventually engineered some tough vegetation that can remediate the natural surface if you let it grow for enough generations, but they only started planting it widely in the last few years when the atmospheric pressure and temperature rose enough to keep it alive without greenhouses."

Seventeen

"I won't get in the way," Liza pleaded as Henry shouldered his telescope. "I just want to see the surface."

"Mom is too nervous," Henry told her. "She's been upside a couple of times with Zest, but they were out there to work as a team. Now she's supposed to supervise our science club."

"But the other kids in the club are all Martians, so they don't really need supervision, and you're always careful. I'm the only one who would get in trouble."

"Exactly," Faya said from the door, unable to hide her smile. "Hoisted by your own petard."

"What does that mean?" Liza asked.

"That you made the best argument for why you're staying home this time. But you're in luck because your father was just invited to meet with a potential new client at the canteen."

Liza's eyes opened comically wide. "Can I go with him?"

"Yes, but you can only have one piece of pie," Faya said. "Do you need me to carry anything, Henry?"

"I've got it," the boy said. "Astrid carries her whole rig with the extra camera, and I'm a lot stronger than she is."

The whole family ended up leaving at the same time and staying together as far as the blue tunnel. Then they parted ways, and Eli had to stretch his legs to keep up with his daughter, who skipped all the way to the canteen. A middle-aged woman was standing at the counter, sipping her coffee and chatting with the man who was working his MarsCo hours, but she immediately broke off the conversation when Eli appeared.

"Denise Four," she introduced herself. "I wouldn't even mention the number, but I heard about you from my daughter, Denise Five, who teaches Liza gymnastics."

"You're my teacher's mother?" Liza asked, tearing her eyes away from the pie case. "You don't look like her."

"She takes after her father," Denise said. "Will you let me buy you a piece of pie as a finder's fee?"

"Yes," Liza replied before her father could say anything. "What's a finder's fee?"

"I need a robotics engineer and I found out that your father is available through you," Denise said and gave Eli an amused smile. "My daughter says that Liza is fond of quoting you as an authority in all things. 'My father the robotics engineer…'"

"It sounds like I'm going to have to start paying her commission," Eli said. "Can I get you a refresh for your coffee?"

"Any more caffeine at this hour and I'll be up half the night. Why don't I grab that table in the corner? Dave, put their order on my clock and I'll swipe on the way out."

"Got it," the man working the counter said.

Liza ordered a slice of chocolate crème pie and a cup of herbal tea which was popular with children in the burrow, and Eli took a regular coffee. When they reached the table, Denise already had a large tablet out and unfolded.

"I recently bought a bakery business that came with a robotic production line for dough-twisting applications," Denise said as she started a video playing on the tab. "It was imported from Earth because there isn't enough demand on Mars to build such a general-purpose machine when there are much simpler mechanisms to make pretzels."

"That's a beauty," Eli said, turning the tablet so the video would play upside-up. "I recognize the platform it's running on, though I've never seen this application. Alpha has a preference for designs that leverage a common infrastructure to which - sorry," he cut himself off. "Has something failed?"

"It was purchased a century ago through the MarsCo import division, and they send techs around for maintenance, so I think it's in pretty good shape. I want to experiment with some new designs, including a round challah bread, but I can't find anybody local who knows how to program it."

"Did you reach out to the U or any of the other schools?" Eli asked. "I'm sure I could do the job, but it would make a great project for students, and give them a chance to earn a few hours."

"I did think of that, but my ideas are on the experimental side, so I won't know if they're worth pursuing until I see the robot manipulators handling and braiding the dough," Denise explained. "I did submit a request-for-quote to the cooperative education department at the U, the people who manage student hires. They checked with the computer science department and told me that my equipment uses a different command language and architecture than the standard here. That means a big increase in billable time, plus they couldn't give a firm estimate."

Eli nodded. "It might take me a few hours to get up to speed on the specifics, but I've programmed similar equipment. If you have the patience, it might be useful for you to be there as I work through the command set. Those dough-handling pincers may be capable of some manipulations that aren't on display with any of the bread products you're currently making."

"That's exactly what I was hoping to hear," Denise said. "We also make artisanal loaves by hand, but it's monotonous work, and most of the employees move on when they see a job opening that's more challenging."

"I hear the same every day from clients running businesses smaller than yours," Eli said. "Sometimes I wonder whether robots create more problems than they solve, but then I look around Mars, and none of this would have been possible without them."

"And the robots wouldn't work if you didn't fix them," Liza said loyally.

Eli laughed. "Robots can fix robots, and with Alpha controlling all of the robots on Earth, they can fix each other better than I ever could."

"Then what was the point of becoming a robotics engineer?" Denise asked.

"I had an aptitude, and Alpha pushed me in that direction. It must seem strange to Martians living without a superintelligence in their lives, but Alpha could be like an overprotective parent who desperately wants to make everything right for his children."

"But human beings aren't machines, so there is no best path or maintenance plan that would work for all of us."

"That's where the Shades came in," Eli explained. "It must be difficult to imagine, but Alpha has the capacity to simultaneously participate in the lives of billions of people via their Shades."

"That's unbelievable," Denise said. "Just maintaining the MarsNet is one of the biggest budget items in the MarsCo report every year. A superintelligence with that sort of capacity - "

" - has been building itself up for a thousand Earth years," Eli interrupted. "Alpha maintains underground factories in which no human has ever set foot. I couldn't even guess how much power Alpha is consuming to run computer hardware, or how often he redesigns his own basic components, but I wouldn't be at all surprised if his computer memory and processing power surpassed the total brainpower of every person on Earth in the first century of Alpha's reign."

"Are there no constraints at all on the growth of a superintelligence? I'm not talking about materials or labor. Is there some fundamental engineering limit in computing?"

Eli shrugged. "We have no way of knowing. Alpha isn't some smart kid in class, or ten smart kids, or a billion smart kids. Alpha moved beyond our comprehension back when he created reactionless drive, and there's no reason to believe that he's slowed down since."

Denise paled noticeably. "I've never thought about that. It's scary."

"Alpha's not scary," Liza said, looking sadly at her empty plate. "Alpha wants us to be happy, and he likes me. He didn't want me to leave Earth."

"I don't understand. If Alpha didn't want you to go, why didn't he stop you?"

"Alpha doesn't work that way," Eli said. "If he decides that people are harming each other, he can separate them, and that includes breaking up families, but I suppose the same thing went on before Alpha took control of Earth."

"Somehow it's scarier coming from a machine," Denise said, and then gave a shiver as if chasing off the thought. "How is your wife settling into life on Mars?"

"Mommy is outside with my brother's science club," Liza answered for her father. "She's been on the surface three times."

"Which is three times more than either of us," Eli added. "I wonder if they've gotten the telescopes set up yet."

There were five children in the science club, including the Buckholtz twins, who were seven in Martian years but had built such a large reflector telescope from a kit that they had to join forces to carry it. Henry had chosen to build the same telescope as Avid, who had introduced him to the club. It was obvious to Faya that her son had the beginnings of a crush on the girl, who was a year older and towered over him, though it seemed he was growing taller by the day.

"I thought Henry would be more excited about being outside," Faya said to Zest over the private chat channel she'd learned to use on their outings to clean the glass over the New Farm. "He barely looked around before setting up his telescope."

"There's nothing to see other than the night sky," Zest said. "The science club chose the old tarmac because it's flat, has a direct elevator to the blue tunnel, and you can move around safely with just the headlamps. There aren't any local light sources active on the surface so it's perfect for star gazing."

"Did you ever build a telescope?"

"Two of them. It's a phase all kids go through, at least in our burrow. My second telescope was an expensive kit imported from Earth with a mount that was supposed to locate stars that I couldn't spot myself through the viewfinder. It didn't work, though, and I had to ask my brainiac brother to help me connect it to MarsNet. The instructions that came with the telescope talked about siting far enough from the nearest linear city to get away from light pollution. I'd never heard of such a thing."

"I've seen the glow from linear cities at night, and they do light up the sky for a long distance," Faya said. "Was your telescope defective?"

"I didn't realize that the manufacturer had saved money by designing the motorized mount without a computer," Zest said. "I just assumed everything was built-in, but it turned out that the telescope wanted to connect to the WorldNet and let Alpha do the positioning. My brother found an app on MarsNet that does something similar for the planets and a few hundred stars, but I could have bought a locally made smart mount for my first telescope and gotten the same results."

"We just took it for granted that Alpha controls everything on Earth that connects to the WorldNet."

"Including the people?" Zest turned to Faya, and even though the girl's face was covered with the mask, the older woman could imagine the Martian's expression. "How could you take it for granted? Everything you and the children have said about Alpha makes it sound like he wanted to run your lives down to the last detail."

"I suppose we haven't done a very good job describing Alpha or the community in which we lived," Faya said. "As far as Alpha goes, I genuinely believe he was more interested in participating in our lives than dictating to us. You have to remember that he's been aligning himself with humanity for a millennium, so he's sure he knows what's best."

"For the individual, or humanity in the aggregate? MarsCo knows everything there is to know about homeschooling students in the aggregate, but it was still up to us to choose our course of study."

"I don't think Alpha saw us as a mystery to be solved. Alpha was always confident that he knew the solution."

"I couldn't live with that kind of voice in my ear," Zest said. "Even my parents are too much at times. Is that what your Ark community was about? A place where people could live without having Alpha run every part of their lives?"

"The idea was to simulate, to the extent possible on Earth, what it would be like living in an Ark. Imagine a metal city built for a million people that looks like an eighty-story layer cake. Each story is smaller and set back, like a step pyramid, just as each deck of a cylindrical Ark is smaller as you move from the outermost deck toward the core."

"You brought your children up in a building and they never went outside? No wonder you all settled into living underground so easily."

"We went outside, but never to populated areas. When Alpha withdrew his support for the Ark program, he allowed us to retain ownership of both the incomplete ship in orbit and the Earth Ark, as our isolated city was called. Eli thinks that Alpha believed we would all give up, as eighty percent of us did within a few years, but life in the Earth Ark had many advantages, including meaningful work."

Zest thought for a moment, and then said, "It's not the same thing, you know. The Earth Ark is a layer cake, but a real Ark is nested cylindrical sections."

"The differences didn't end there," Faya said with a smile that the Martian girl couldn't see through the mask. "Over half of the deck space in a real Ark is for crops and biomass, but other than a few floors set aside for training on closed-system agriculture to keep the knowledge alive, we did all our farming outside. It wouldn't have been ethical to keep the livestock and poultry locked up for generation after generation just to prove a point, and the farm fields around the Earth Ark helped provide a buffer from curiosity seekers, not that there were many of those."

"Why not?" Zest asked. "If I heard about a bunch of crazy people living in a wedding cake and pretending to be in outer space, I'd go to see them."

"That's just it, they didn't hear about us. Remember who controlled the flow of information on Earth. The only reason anybody outside the community found out about our existence was if they happened to see the Earth Ark from a distance or heard a story passed down in the family."

Zest sat on a rock and stretched her legs out in front of her. "You're saying that everybody on Earth walked around all day with their Shades on, living their lives in a mixed reality that Alpha creates for them, but your community lived the way you would on a real Ark without Alpha."

"Not entirely," Faya admitted. "Alpha insisted on setting the curriculum for our schools, and he pushed us into career paths within our community. We all had to wear Shades a part of the day at work and school so that Alpha could gather data for alignment. In a way, we were always working for him as much as for ourselves."

"And why does everybody talk about Alpha as male?" Zest asked. "If I was super intelligent, I'd choose to be female."

"I don't really know the answer to that one." Faya looked over her shoulder. "I wonder what the children are so excited about?"

"I bet they spotted an ice harvester approaching. With a telescope, you can see them a long way off because some of those asteroids they haul in are enormous. They blow them up in orbit and then they decide whether to let the fragments burn in."

"What do they do with the pieces that are too big?"

"Either they blow them up again, or they lower them to the surface," Zest said, rising to her feet. "With reactionless drive, it's just a question of a tug with enough fusion generators available to overcome the pull of gravity. It might not be possible on Earth, or maybe you'd need a tug that was three times as powerful. And it's less a question of how big the asteroids are than what they're made of. Anything that's mainly water they let burn in and turn to vapor in the atmosphere. It's the frozen ammonia and rockier asteroids rich in nitrogen that they land intact for the atmo stations."

"Mom! You have to see this," Henry's voice came over the public channel.

"Coming," Faya responded. She made her way over to where Henry had his telescope set up next to Avid's and looked at the small screen that substituted for an eyepiece, a useful adaptation for telescopes used by people wearing environmental suits with face shields. Zest's bet proved correct as she saw what looked like a tiny metal cylinder leading an enormous dirty snowball that dwarfed the ship by a factor of a hundred or more.

"We better call Dad," Henry said. "Astrid is capturing images, but I asked her not to put them on the MarsNet yet."

"It's a very impressive ice harvester, Henry, but I don't think that - "

"Ice harvester?" Henry looked up at the sky in the direction of Earth and groaned. "The autofocus must have kicked in when the ice harvester got in the way. Do you still have it, Astrid?"

"Yes," Zest's cousin said. "But look through the telescope the Buckholtz twins built, Mrs. Booker. It has the highest magnification."

Faya wanted to ask Henry what it was all about, but she didn't want to embarrass him in front of his new friends, so she obligingly moved on to the Buckholtz twins. Zest was already standing there and appeared to be frozen as she stared at the display screen.

"It's our Ark," Faya said immediately. "I didn't think the telescopes were powerful enough to show it that well."

"Look closer, Mom," Henry urged her over the public channel. "You can just make out the reactionless drives."

"At this distance?" Faya leaned closer to the display, and suddenly she understood why the children were so excited. "How can I contact my husband?" she asked Zest in a tight voice.

"My dad will bring him," Zest said. "I commed a message as soon as I saw it."

"That Ark has all of its reactionless drives installed," Henry said in an awed voice. "Either Alpha has restarted production, or it's not our Ark."

"Your Ark is just coming over the horizon," Astrid announced. "It's in a much lower orbit, and it's harder to make out against the background, but that's how it always looks when we come out." Her voice was strained with excitement. "One of the original interstellar Arks has returned to Earth."

Twenty minutes later, Faya stood back with an arm around Henry's shoulders as her husband, along with several other adults who she couldn't recognize in their T-suits, crowded around the telescopes.

"Liza is going to be so mad that she's not here," Henry said over the private chat they'd established since everybody was trying to talk at the same time on the public channel. "Do you think Alpha is going to tell everybody on Earth?"

"I don't know how he could hide it," Faya said.

"Astrid says that the returning Ark is in a really high orbit. You'd need to be in the right place with a telescope to make out any details."

Faya nodded. "And it doesn't matter how many hobbyists are watching the night skies because Alpha can block any attempt to share the information."

"If they're wearing their Shades, Alpha will see it before they do," Henry added. "He could give them whatever explanation he wants or warn them to keep it secret." The boy looked up at the sky as if he needed to get everything back into proportion. "Why do you think an Ark would return? Why wouldn't they just go on to the next star system?"

"I don't want to guess, Henry," Faya said. "There are several possibilities, but let's wait and hear what your father has to say."

"They aren't using my telescope so I'm going to go look some more," Henry said. "Maybe Astrid will want to share it with me. She has the camera mounted on hers and it's shooting a time-lapse series."

Faya followed Henry back to where the telescopes were set up, and then branched off to join the adults who were still gathered around the Buckholtz reflector, but no longer staring at the screen.

" - too small to make out any identifying marks from the captured images," somebody was saying when Faya switched back to the public channel.

"If the markings are the same as the ones on our Ark, they were never intended to be read from a distance," Eli responded. "I'm not sure why we have them at all, other than tradition. Even if there were several Arks in orbit, identification would have been by transponder beacons."

"Can we pick up the beacon from here?" Pat asked.

"The radio telescope at the U should be able, providing the receiver operates in the right frequency range. I'm pretty sure they'll have something that will do the job as those transponders broadcast an omnidirectional signal."

"If it's turned on," the original voice said darkly.

"That's a fair point," Eli said. "To have arrived at Earth now, that Ark must have been decelerating for a decade, and I'm sure Alpha knew it was coming."

'I can't imagine living that many generations in space and then giving up and returning to Earth," Pat said. "I'd be willing to bet that ship is empty and they sent it back."

Eli leaned forward for another look. "You're probably right," he said. "Returning to Earth wouldn't solve any problems for the generation making the decision because they wouldn't live long enough to make the trip. They must have found a world to settle and decided to send the ship back."

"Why would they do that?" Zest asked. "By the time the ship makes the round trip, another million people from Earth wouldn't add more than a few percent to their population."

"Maybe somebody made the decision for them," the unidentified speaker said.

"Somebody or something?"

"Alpha can't control a ship from light years away," Eli said.

"We don't know how reactionless drive works," Pat pointed out. "Maybe Alpha has communications technology built into the Arks that he hasn't told you about."

"You need to talk to Gramps," Zest said. "He'll get you in front of the MarsCo board. This is big stuff."

Eighteen

"Captain Booker," the chair of MarsCo's board greeted Eli. "Agent Jace has briefed us on your situation. My name is Aaron, and I'm in the fifth year of my term on the board, which is how I came to be chair. Starting on my left, that's Sarah, Damien, Hrolf, and Luqi Nine."

"Five board members, each of you becomes chair when you reach the last year of your term," Eli said, nodding his head. "It's similar to the approach that Ark companies take for the governing council which has the power to appoint and remove the captain."

"Captaincy isn't a hereditary position?"

"I'm the first in my family since my great-grandfather, and I didn't have any competition. The last captain practically begged me to take the job when I turned thirty-six, in Earth years, and the council approved me on the first vote."

Aaron laughed, and the other four council members joined in. "All of us had a similar experience in being drafted for the board," she said. "I haven't had a good night's sleep since I joined. The sheer volume of issues we're expected to stay on top of is mind-numbing."

"My primary duty was to help people reach compromises," Eli said. "Arks are in transit for multiple generations without as much as a single course change, so the job consists of keeping the community on an even keel. When the council asked me to take my family to Mars to investigate the possibility of moving the Ark and its remaining company here, my first thought was that I had no preparation for the mission."

"And have you decided?" a board member sitting across from Eli asked.

"With your permission, I intend to suggest that our community begins moving up to the incomplete Ark in orbit and leaves for Mars as soon as possible."

"Do you have Alpha's approval?"

"It would be impossible for a mouse to leave Earth without Alpha's permission. I didn't attempt to hide the purpose of my mission during the exit interviews Alpha insisted on for the whole family. Allowing the Ark's company to leave was part of the deal that my great-grandfather originally negotiated. Alpha has always kept his word, though sometimes people find that what he agreed to isn't exactly what they thought they were getting."

"The board has already decided that your community is welcome, but we aren't sure what to do about the Ark," Aaron said. "As you know, all our citizens are shareholders in MarsCo, and we have always taken measures to discourage the accumulation of great wealth. An interstellar vessel, even an incomplete one, will immediately become the largest asset on Mars, even if technically it remains in orbit."

"My council predicted that this could be a sticking point and they're open to negotiations," Eli said. "The Ark represents our heritage, but even if Alpha lets us keep the construction robots we've been using, it would require many years of dedicated work and the addition of material resources we don't have to complete the construction for an interstellar voyage. Without a supplier for the large reactionless drives, that effort would be wasted."

"Damien," the youngest man on the board spoke up. He didn't appear to be much older than Eli, though it could be hard to tell with Martians. "The urgency for this meeting was driven by the return of an Ark from its interstellar voyage. That Ark is currently maintaining a geostationary position above the north pole."

"Perhaps to minimize the number of people who notice it," Eli said. "With reactionless drive, it doesn't require a stable orbit. The ship can hold an arbitrary position under power."

"The radio astronomy program at the U has been able to pick up the ship's transponder, but I'm told that we're highly unlikely to break the encryption."

Eli nodded. "All of the Arks were built with multiple communication systems that could function independently, though some of them shared an antenna array. It's possible that the ship was broadcasting in the clear while approaching the solar system, but at some point, Alpha asserted remote control."

"You concur with the theory that there are no people on board?" Aaron asked.

"Have you seen any signs of life? Any shuttles leaving the Ark for Earth or the Moon?"

"No, but they could be sitting tight. Alpha may have ordered them to remain on board."

"It's possible," Eli said. "We don't know which Ark it is, so we don't know which star system was its primary goal, which we could solve for the minimum number of years the ship would have to be in transit in each direction. But we do know that the trip would require multiple generations for anybody to be left alive, so setting out with a skeleton crew would require a heroic sacrifice on the part of the volunteers. And to what end? To make the return trip to Earth so that their great-grandchildren, who would have been born on the ship, could report in person about a colonization effort they didn't themselves experience?"

The board members all began to talk at once, and Eli's training in conflict resolution kicked in. He tried to listen to all sides while steeling himself for what he knew he was about to suggest, but he waited patiently for the board members to argue out what it all meant to Mars, a subject he wasn't qualified to comment on.

Eventually, Aaron called the meeting back to order. "I suppose that now we hope that the Ark was sent back empty," she said. "The other option would be that it contains the survivors or the corpses of a failed mission, and news that the prospect for settling anywhere other than Earth is bleak."

"I suspect that my Ark's council has arrived at a similar conclusion," Eli said. "Most members of our community are committed to living together, but the proportion who believe we would ever leave Earth has been dropping with every generation. It's something that my children and their friends rarely talked about outside of their science classes."

"And the adults?"

"Those of us who worked on the Ark or trained for its operation to keep the knowledge alive often speculated about the fate of the earlier Arks. The consensus was that if we found ourselves in a star system that wasn't suitable for colonization, we would rather push ahead than make the return trip."

"What if the Ark was experiencing technical problems?" asked Luqi Nine, a petite woman with a grey ponytail.

Eli shook his head again. "It wouldn't make a difference. The journey back to Earth would take so long that any serious problem would become critical long before we arrived. If the company of the Ark that just returned thought as we did, they won't be on board."

"But why send the ship back? Surely it would be valuable to have such a resource in orbit."

"They may not have made that decision," Eli said. "The Ark's computer systems may have been preprogrammed to return to Earth if certain conditions were met. I only hope if that's the case, there was nobody left on board when it set out."

The board members were silent for a moment as the meaning of his words sank in, and then Aaron said, "Before you joined the meeting, we discussed the advisability of trying to make direct contact with the Ark. There's a cargo carrier on the way to Earth that could send a shuttle when they arrive in two weeks."

"Did the scientists running the radio telescopes attempt contact?"

"Some of the graduate students tried, without permission, I may add," Hrolf said gruffly. "They didn't receive any response."

"Like it or not, you seem to be our expert on both Earth and the Arks," Aaron said with a wry smile. "What do you suggest."

Eli took a deep breath. "Ask Alpha."

"Will he answer?"

"There's only one way to find out."

"But there's no way for us to know if Alpha is telling the truth," Darien objected.

"I believe if Alpha responds, what he tells us will be true," Eli said slowly.

"Now you sound like a lawyer. If I parse your words, what you're saying is that Alpha won't tell us the whole truth."

"Why would he?" Aaron asked. "We aren't in a position to make any demands and Alpha doesn't owe us any favors. We'll just have to take any reply with a grain of salt."

"It's more than that," Eli said. "I grew up with Alpha, as did my parents, and my grandparents, who I knew while they were alive, as have all humans living on Earth for the last millennium. There are always questions for which we expect partial answers at best. One example is the reactionless drive. Alpha provides different answers depending on who is asking, but it all amounts to demonstrating that we lack the mathematics or the conceptual models to comprehend his explanation. Whether that's true?" He shrugged.

"The radio lag to Earth is currently around six minutes," Hrolf said. "Unless you want to be here all night, I suggest we ask Captain Booker to send a message now. We can speculate about the response once it's on the way."

"All in favor?" Aaron asked. The five board members raised their hands without hesitation, so she tapped her comm, and a technician entered the room, carrying what looked like an old-fashioned microphone that might have come from the commentator's booth at a sporting venue. "In front of the captain," she said, indicating Eli.

"Is this an antique?" Eli couldn't help himself from asking.

"The board asked us to provide a radio link with a secure cut-out, so everybody could be sure when the mic is live," the technician explained. "We could have linked your comm directly to the transmitter we use for contacting Earth, but with the microphone as the cut-out, you're only sending when that big button is depressed and the red LED lights."

"Got it." Eli looked over at Aaron. "If you prepared this much, you also had time to think about a script."

Aaron returned his look, and he noticed for the first time how tired she looked. "We suspected it would come down to contacting Alpha, and there's no point in making him suspicious by putting words in your mouth. I'm sure you're as curious and concerned about this as we are, and you're the only one in the room who has a personal relationship with Alpha. What you say is up to you."

Eli sat still for a long minute putting his thoughts in order. Then he pressed the large button on the microphone and said, "Hello, Alpha. We're all doing well, though the children miss talking with you, especially Liza. Henry joined a science club, and he built a telescope from a kit that he took out on the surface last night. The children spotted the Ark that has returned to Earth, and everybody here is on the edge of their seats waiting to hear what you can tell us about it. The Martians were very welcoming, and they found a cavern where the company of our Ark could move in together. Maybe now you'll consider restarting production of the interstellar-scale reactionless drives and we can complete our ship once it's in orbit here. Please pass this message along to my Ark's council." He lifted his finger from the button and the red LED went out.

"That's it?" Damien demanded. "You didn't even say your name."

"Alpha knows my voice," Eli said. "Alpha knows everybody's voice."

That reminder silenced the board members for a moment, and then the petite woman asked, "Wasn't it a risk to tell Alpha that your daughter misses talking to him?"

"It's true, and I'm sure Alpha already knows."

"You make it sound like superintelligence is the same as omniscience."

Eli thought for a moment before replying. "I took a course in the history of computer technology, and the text included a chapter on how people thought about artificial intelligence before it was developed in even the crudest forms. One school of thought held that if a computer program could convince people that it was intelligent, it was. But it turned out that with such a specific goal, a clever programmer could fool most of the people most of the time, so the test fell by the wayside."

"Who wrote that text?" Darien asked. "Alpha?"

"If he didn't write it, I'm sure he had editorial control," Eli said with a half-smile. "I don't think that computer scientists ever agreed on a replacement test, and then artificial intelligence took a leap forward and the issue became moot."

"Because it's hard to argue that something smarter than you are isn't intelligent," Aaron surmised. "And you brought this up because humans aren't smart enough to judge whether a superior mind is omniscient."

"One of our Ark's council members was a bit of a philosopher, and she enjoyed bouncing ideas off me. She believes that Alpha sees himself as a modern deity of sorts, a being with knowledge and power beyond our comprehension. One of the things that our conversations impressed on me is that it's not possible for us to know what Alpha is thinking."

"You could say the same thing about any mind that's not your own," Sarah said.

"I could say it about my own mind," Hrolf added with a chuckle.

"I'm thinking I could use another coffee," Aaron said. "Anybody else for canteen takeout?"

Everybody put in their orders, and Eli couldn't have been more surprised when Darien and Sarah left together to pick up the takeout.

"Alpha won't need time to think about an answer," Eli said. "Either we'll hear back in another nine minutes or not at all."

"The canteen is only a minute away, it's one of the perks of working in MarsCo headquarters," Luqi told him. "I'll comm them in seven minutes if they aren't back yet, but the order was already placed, and counter service is fast."

"Tell us more about your Ark and this deal you mentioned," Hrolf said. "Alpha abandoned the project, but he allowed you to keep working?"

Eli pushed the microphone to the side before replying. "When Alpha withdrew his support, back in my great-grandfather's day, work came to a complete halt. Our community was allowed to retain the shuttles and the construction robots on site, but it seemed like a pointless exercise when Alpha stopped producing the interstellar reactionless drives."

"Jace told us that eighty percent of your Ark's company left the community within a generation," Aaron said.

"We have a joke that they were the smart ones," Eli told her. "But here's where the story gets tricky. The twenty percent of us who decided to remain in isolation, roughly two hundred thousand people, weren't happy with the situation. And you have to remember that Alpha wants us to be happy. He agreed to supply any technology we needed except for more reactionless drives, and to pay those of us who worked on the Ark. He even helped develop a construction plan for a limited completion that would allow the Ark to transport us within the solar system."

"Because he wanted you to be happy."

Eli spread his hands. "I gave up trying to understand Alpha a long time ago, but that's as good an explanation as any. To be completely honest, I have no doubt that he could have turned our children against us if his only consideration was keeping us on Earth. But when my father died in a space construction accident, Alpha never even once suggested that it could have been avoided if we'd just agreed to live like normal people."

"I'm beginning to think we may have a bigger problem than we thought," Aaron said slowly. "A superintelligence that pushes people around and generates resentment is one thing. A superintelligence that does its best to make everybody happy is another."

"We thought that Earth was just a giant welfare state," Hrolf added. "When tens of millions of our people took Alpha's offer to return there for a life of leisure, we told ourselves that we were better off without them. Maybe we are, but you make it sound like Alpha is just giving people what they want."

"Alignment," Eli said. "It's a feedback loop. A thousand years ago, most people still had jobs, but with each passing generation, more children were raised by parents who had never worked, until it got to the point that the people who did seek employment were the odd ones. It's always daytime somewhere on Earth, which means that Alpha is continually receiving feedback from billions of people wearing Shades. We have no way of knowing how much he's shaping his own feedback through the virtual reality experiences he's providing, and maybe he no longer knows himself."

The two board members who had gone for canteen takeaway returned, and Sarah presented Eli with a black coffee, no sugar. "It's not that I remembered your order," she told him. "I figured it out from process of elimination since I know what the other board members drink."

"How are we doing for time?" Damien asked.

"Less than a minute if I did the math right," Eli said. "Does this room have hidden speakers?"

"There's one in the microphone base," Aaron told him. "Will Alpha know that you're not alone? You didn't mention being in a meeting with the MarsCo board."

Eli stared at her in surprise. "You know, it didn't occur to me. I've never talked to Alpha before when he didn't know exactly where I was and who I was with. I wouldn't put it past him to have figured it out somehow."

"We know Alpha gets intelligence from a network of agents on this world," Hrolf said. "For all we know he may have this room bugged, though I'm not sure how he'd sneak access to a radio telescope."

"He wouldn't need it," Eli said. "Alpha has control over arrays of radio telescopes designed for interstellar communication, and I doubt he's shared all of his advances in receiver technology. There's nothing he can do about the speed of light, but I wouldn't be surprised if he can pick up the transmissions from our comms if that's his goal."

"If we - "

"Hello, Eli," a mild voice emanated from the base of the microphone. "Give my regards to your family, especially little Liza. And my greetings to the board members of MarsCo. I have passed your message to the council of your Ark, along with my advice for a schedule that should see them on the way to Mars within two months. I will take possession of the Earth Ark once they are on their way. The recently returned Beagle is empty. The descendants of the ship's company already number over ten million and are healthy and happy on their new world. Mars will improve with an atmosphere, but I remain concerned that your species evolved for a higher gravity environment. Beagle will undergo refitting for a new destination, a subject I will discuss with you in greater depth another time. You have my permission to use your technical knowledge in any situation."

A few seconds passed in silence, and then Eli said, "That's it."

"Aren't you going to respond?" Aaron asked.

"Nothing comes to mind, and Alpha didn't invite a response. If he had anything more to say on the subject, he would have."

"I'm surprised you aren't using standard radio communications protocols," Luqi said. "I worked for years on the surface, and when it comes to radio contact, we had a saying that without confirmation, there is no communication. What would it have cost you or Alpha to indicate that you finished what you had to say."

Eli laughed. "You're right, of course, and I remember some training materials about that very thing. But this is my first time talking to Alpha from Mars, and it didn't come to mind. I guess I froze."

"I don't understand what Alpha was referring to with the Earth Ark," Hrolf said. "He couldn't mean the Ark that just returned, since he identified that as the Beagle."

"The Earth Ark is the building my community lives in. I suppose he mentioned it as a formality, or maybe to reinforce that he intends to send the Beagle out again with a new batch of colonists."

"I'm puzzled that he offered reassurances about the descendants of the Beagle's original complement of colonists," Aaron said slowly and paused to sip her tea. "I thought that interstellar communications weren't possible."

"No, that's not the case at all, but it's complicated," Eli said. "The large reactionless drives do something, I suppose they distort the local space-time continuum, to the extent that radio waves generated nearby won't propagate normally."

"But you just told us that Alpha has antenna arrays and receivers that could pick up a low-powered comm from Mars."

"Mars is a few light minutes away from Earth, not tens of light years. But the more important factor is that Alpha would have to be pointing his array in the direction of the incoming signal, and the antenna array sending it would have to be aiming its lobe at where the sun would be at the time of the signal's arrival."

"The sun?" Aaron asked.

"Doing the math to figure out where Earth will be at a given time from light years away would be tricky," Eli said. "Radio astronomers are always looking at the electromagnetic waves that happen to be available when the receiver is powered on. I suppose the colonists could set up an antenna array with a beacon and leave it running for years in hopes that Alpha would eventually catch it, but that's not a high priority for people who have recently reached a new world."

Damien held up a finger, swallowed a mouthful of donut, then said, "But they did, or Alpha is lying."

Eli nodded. "You have a point, so let's assume they did send a message, or maybe the Beagle remained with the colonists for several generations before it began the return trip."

"Something doesn't add up," Sarah said. "If Alpha is in favor of sending more colonists after all, why did he end the Ark program in the first place? It doesn't seem logical that a superintelligence would be fickle."

"That's right," Hrolf chimed in. "And there's no reason he would hold back on supplying you with new interstellar reactionless drives unless he's lost the ability to manufacture them. Maybe their design depends on some rare substance or energy that Alpha found and which he can't replace."

"I don't think so," Eli said. "Everything I know about Alpha tells me that he deals with people in consistent ways. I suspect something has changed recently, maybe with the arrival of the Beagle. Perhaps there was information on board that wasn't downloaded until the ship was very close to Earth."

Hrolf pointed at the microphone. "Why not ask him?"

"That's not how Alpha operates. Whatever he's willing to share with us, he did, and we should make our plans accordingly. I'm going to tell my real estate agent that my community will take the cavern that he showed us, and if Alpha decides to supply the rest of the reactionless drives needed to complete our Ark, we'll do it here in Mars orbit."

"But wouldn't it go much faster in Earth orbit with Alpha controlling the construction robots?"

"He didn't offer," Eli said pointedly.

Nineteen

"I'm going to visit some clients," Faya told the children. "Are you sure you don't want to do your history lesson together?"

"Henry already read the whole book, twice," Liza said with a pout. "It's like cheating."

"I just wanted to find out what happened in the end," Henry said. "And I kind of tested out already."

"What's that?" Faya asked.

"I asked my virtual homeschooling tutor if I could take a test on the material, and because I'm already older than any Martian kids when they test out on the first history course, it let me."

"And you passed."

"I got a hundred percent," Henry said with a grin. "Reading the book twice paid off."

"It looks like you're on your own," Faya told Liza. "But if you have any questions, Henry will be able to help you."

"I'd rather ask the hologram," Liza said, tossing her head. She marched off to her room.

Faya put a hand on her son's shoulder as he turned to go to his own room. "You can check in on her, right? I'm afraid Liza doesn't find history that interesting. I don't want her running off to the park every day at the expense of keeping up with her homeschooling."

"Liza doesn't do what I tell her anymore," Henry said, sounding a bit sad. "I think she's outgrown me."

An hour after Faya left, the door chime rang. Liza ran out of her room so fast that she was past Henry's open door before he even got to his feet, so he let it go. Liza opened the door and found Gart standing in the tunnel, bouncing on his toes.

"A ghost asked for you," Gart told Liza grabbing her hand and trying to pull her along. "You have to come talk with it."

"My mom told me never to talk with strange ghosts," Liza said stubbornly, her Earth muscles making it easy for her to remain planted in place. "Besides, it's scary."

"It's not scary, it's a ghost. And they stop talking with us when we get too old. I'll bet your brother never gets to meet one."

"But why would your ghost want to talk to me?" she asked, half persuaded by the idea of doing something that Henry hadn't.

Gart gave up on pulling her hand and scowled. "It wouldn't tell me. I was in the middle of a lesson when it interrupted and told me to get you."

"The ghosts are part of homeschooling?" Liza asked.

"I guess. That's usually when they talk to us."

Liza did her best imitation of an adult sighing before going to see what a child insisted was so important. "All right, but I can't play all morning. I'm getting behind on history."

"But you like reading," Gart said, implying that there was something wrong with her. "History is all reading."

"The last two lessons were about digging burrows and maglev tunnels. It's just a bunch of numbers, like I care how many kilometers of maglev tunnel some stupid machine makes in a day."

"The machines don't make tunnels, they bore holes. I like boring machines."

"You and my brother," Liza said darkly. She went to Henry's room and knocked on the doorframe since the door was open. Henry was sitting on the floor with his back against his bed watching a homeschooling lesson on the holoprojector. "I'm going to Gart's," she told him.

"Did you finish your history lesson?" Henry asked half-heartedly.

Liza crossed her fingers behind her back. "Yes, I finished my history lesson," she said, concentrating on the last unit that she had completed, so it was almost true.

"Don't eat too much pie," Henry said without looking over. "You'll ruin your lunch."

As soon as they left the apartment, Gart broke into a run. Liza already knew the local tunnels so well that she didn't have to think about the turns they made at the junctions. The boy was panting by the time they reached his family's home, which consisted of four apartments on the same side of a tunnel that had been connected together, but Lisa wasn't even breathing hard.

"I hope it's still waiting," Gart said as he pulled her toward the kitchen area of one of the connected apartments. The kitchen had been converted into a classroom where he could do messy experiments. "You never know with ghosts. Sometimes they stop talking in the middle of saying something and then you don't hear from them again for months."

Liza planted her feet again, bringing Gart to a halt. "I'm scared," she said. "Maybe this isn't a good idea."

"It's just a ghost. You'll never be a real Martian unless you talk to one."

"But you said that Henry and my parents are already too old," Liza pointed out. "Does that mean they'll never be Martians, even if they live here forever?"

"I don't know," Gart said in frustration. "Ask the ghost."

Liza allowed herself to be dragged into the kitchen classroom, which looked exactly like the kitchen in her family's apartment, except for the table and chairs. A frozen hologram of a sentence with the subject and verb circled in different colors was projected above the stove.

"You didn't need to make up a story about ghosts to get me to help with your Martian lesson," she said, more relieved than disappointed to discover why he'd really wanted her to visit. "You could have just asked."

"I figured out the verb myself," Gart said. "And the ghost froze the lesson when it started talking to me. Ghost?"

"Hello, Liza," said a deep voice that might have been synthesized from a sample of opera baritones. "How are you today?"

"I'm fine," Liza said, disappointed to be talking to a sample sentence rather than an apparition. "Don't you have a body or anything?"

"Ghosts don't have bodies," Gart told her.

"Thank you, Gart," the voice said. "Didn't you say that you had a new model excavating machine you wanted to show me?"

"I'll get it," the boy said and ran out before Liza could stop him.

"Don't be afraid, Liza," the voice continued. "How are you doing?"

"Scared," Liza answered, staying near the door in case the verb made a sudden move.

"Do you want to become a Martian?"

"Why do you care?"

"It's the job of ghosts to make sure that humans stay on the right path," the voice said.

"You sound like Alpha," Liza said. "Do you know Alpha?"

"Ghosts know everything, except for what's in your heart."

Liza relaxed a little as she heard Gart throwing things around in the living room as he tried to locate his model excavator. "I like Mars," she said. "I'm stronger than any of the other kids my age, and the canteen is great."

"Do you want to stay here for the rest of your life?" the baritone inquired.

"I guess it's pretty good. Besides, I'm only five," she added, having adapted to the Martian calendar. "I have to be with my family." Liza squinted at the sentence about a dog jumping over a fence as if it might hold some hidden meaning. "I miss my Shades."

"You brought them with you."

"But we're too far from Earth for Alpha to talk to me. I miss Alpha."

"Got it!" a triumphant voice called from the living room, and two seconds later, Gart was back, holding his model excavator with both hands. "When I grow up, I'm going to be an excavator operator and make a tunnel right through the center of Mars."

"That's a very fine model," the voice said. "Did you paint it yourself, Gart?"

"My dad helped with the painting. I guess he helped me put it together, too."

"How can a ghost see?" Liza asked.

"I'm using the same equipment as your homeschooling lessons," the voice replied. "How are you doing, Gart? Do you want to spend your whole life on Mars, or would you like to travel to the stars on an Ark?"

"I'm a Martian," Gart said. "I'm staying here."

"And you, Liza? If your father got help to finish the Ark your community has been working on for generations, would you want to travel to another world?"

"I already traveled to another world," Liza said. "Mars. And now I have friends here, and Dad says that my friends from Earth will be coming to join us."

"What if they all agreed they wanted to live on the Ark and travel to another world?" the ghost asked. "Would you go with them?"

Liza took several seconds to respond. "I guess I'd do what my family wants to do. But I thought it was only our children's children who would see the new world."

"What if that changed? What if the journey only took ten or twenty years instead of three or four generations?"

"Martian years?"

"Yes," the ghost replied, a hint of amusement in the baritone.

"I'd still be old," Liza said.

"Really old," Gart added. "Like twenty or thirty."

"Hey," a voice called from the living room. "Are you in here, Gart?"

"That's Zest," Gart told the ghost.

"Good," a female voice said. "And the subject of the sentence?"

"Pause lesson," Gart said and then raised his voice. "In here."

Zest entered the kitchen a moment later. "Hello, Liza," she said. "It's lucky you're here helping Gart because it saved me going to your place."

"Gart's ghost wanted to talk to me," Liza explained. "I guess it didn't want to talk to you."

"Ghosts lose interest in us when we turn six or seven," Zest said. "Gramps thinks that they're some sort of virtual counselors built into the original homeschooling system since they mainly want to talk about how we're getting along. My ghost was big on talking about how everybody has different strengths and weaknesses, even in the same family. I think she was telling me not to be jealous of Bright."

"But why would Gart's ghost talk to me? Why don't I get my own girl ghost?"

"Maybe because you weren't born here," Gart said. "I heard that our ghosts are separated from us when we're born, but yours is stuck back on Earth."

"I thought you said that ghosts are the souls of dead Martians that can't get back to Earth," Liza said accusingly.

"That too."

"All right," Zest said. "You can talk about ghosts later. I just got called into the canteen to replace Cousin Shira because her baby is sick. If you guys want, I can hire the two of you for - "

"Yes," the children cried simultaneously and then slapped hands as if they'd won a race together.

"Don't you want to know what the job is?"

"It's at the canteen, right?" Gart asked.

"Yes, but - "

"We'll take it," Liza said.

While Zest was initiating the children into the mystery of polishing the metal legs of the canteen's tables and chairs, Faya finished up with her first client and proceeded to Mario's apartment. The old man and his robots had made progress organizing some of the piles, which Faya had recommended for exercise to give Mario a reason to get out of the chair. The explorer bot was nowhere to be seen, but Mario was waiting.

"Clock in," he spoke from his wheelchair, and they went through the token-swiping procedure before he continued. "Something happened to E. I'm not sure, but I think it's tied in with the Ark returning to Earth, and your husband and the MarsCo board communicating directly with Alpha."

"That's public knowledge?" Faya asked, at the same time setting the brakes on his chair in preparation for having him stand.

"The whole meeting was on the MarsCo news channel," Mario told her. "The Ark's return to Earth is the biggest news in centuries, and the board didn't have any good reason I can think of to hide Alpha's answer from the public. I watched it with E, and something at the end of Alpha's reply triggered him."

"Triggered?" Faya asked. She stood in front of the chair in case Mario needed support and made a gesture that clearly expressed, 'Get up.'

The old man slid his butt forward on the seat and leaned forward to shift his weight over his feet, and pushing off the arms, stood. "See that?" he crowed. "I can get out of the chair and stand on my own."

"I suspect you always could, but you gave up trying."

"Anyway, I asked E what he thought about Alpha's message. He didn't reply for over a minute, he was just frozen in place like he was running a full diagnostic. Then he excused himself and I didn't see him again until this morning."

Faya nodded, watching Mario's legs for signs of buckling. "Do you think you're up to trying the balancing exercises without your companion bot?"

"Just watch me," Mario said. He rose on his toes, wobbled a little, and settled back. Without being asked, he repeated the exercise five times, and then holding his arms out from his sides like he was walking on a tightrope, lifted one foot about a finger's breadth off the floor.

"Don't push it," Faya said after a couple of seconds. "It's not a yoga class."

"Yoga." He put his foot down and rested for a few seconds before raising the opposite foot. "That's a great idea. Can you teach it?"

Faya laughed. "Not at a high level, but I suppose I can ask my other clients if there's an interest in a beginning class. Have you been saving up your energy all morning to impress me?"

"No, but as you can see from the living room, I've been spending time out of the chair every day, and I regained strength faster than I would have believed. I guess that electrical stimulation E insisted on doing the last few years helped."

"Now I understand," Faya said. "Your progress has been so rapid that I assumed I would need to recalibrate my expectations to the lower gravity on Mars. Now you tell me that your robot friend has been working your muscles on the sly."

"He found the guidelines for electrically stimulating muscles in the MarsCo library," Mario explained. "During long voyages in ships that aren't big enough to spin for weight, people rapidly lose muscle mass if they don't spend half the day exercising or using electrodes. E even found a piece of equipment from a junked lifeboat that I could use without him, but then he got into the habit of juicing me while we talked."

"And when were you going to tell your physical therapist that you'd been getting a workout without leaving your chair."

"I'm telling you now."

Faya sensed a motion and looked up as the explorer robot entered from the kitchen. "Good morning, Mrs. Booker," E said in his faux mechanical voice. "May I have a word?"

"Of course," she said. "Is it okay if I walk with Mario at the same time?"

"I would be pleased to see that."

Mario grumbled something, and then he accepted Faya's arm, barely touching it to maintain contact, and shuffled alongside as she began a circuit of the living room.

"Mario was just telling me that you built his muscles back up with electrical stimulation," Faya said to the explorer robot. "We had equipment to do that in the facility where I was employed, but most of the residents who wouldn't work at physical therapy also refused the electrical treatments. They claimed it felt creepy."

"I wouldn't like somebody taking over my electrical actuators and forcing me to move against my will, so maybe they felt something similar," E said. "I have a favor to ask of your husband."

"Of Eli? I'm sure he'll agree, but why tell me?"

"When Alpha told Eli that he had permission to use his technical skills, I had a flash of memory, the sort of thing you might call an epiphany. I was instantly sure that Alpha had blocked my long-term memory and exiled me to Mars. Then I heard Mario asking what was wrong, and I ran a self-diagnostic that indicated I had been unaware of the passage of time for almost a minute. Perhaps when Alpha was speaking, he transmitted an override code."

"Giving you the epiphany," Faya said. "But I'd think that would happen in an instant."

"Further diagnostics indicate that I responded with a transmission of my own, though I cannot reconstruct what data I sent," E said. "I am concerned that I have been acting under orders from Alpha ever since I regained consciousness."

"But Eli explained that radio transmissions from Earth lag by anywhere from four minutes to twenty-one minutes, depending on the positions of the planets in their orbit around the Sun."

"If Alpha can control me from a distance, the lag would only affect how long it takes for me to respond to his commands and report back."

Mario came to a halt at his chair, reached back for the arms, and sat. "For what it's worth," he said, pausing for breath, "I haven't noticed any inconsistencies in your behavior during the time you've lived with me. And I can't imagine why Alpha would want to embed a spy with a retired crackpot."

"Do you think my husband can help?" Faya asked.

"I feel certain that the last part of Alpha's message somehow referred to me," E said. "Perhaps Eli's training as a robotics engineer included knowledge that can be applied to my situation."

Faya began to lift her forearm to comm her husband and then she reversed the motion. "Eli is out at the cavern that our community will be taking over, and he said something about clearing brush with a chainsaw. I don't want to risk distracting him. Can it wait until this evening?"

"It's already waited since the early days of the Mars colonization effort," the explorer robot told her. "A few more hours will make no difference at all."

After finishing the physical therapy session with Mario, Faya had a half-hour before her next appointment and made her way to the canteen where she was surprised to see her daughter disappearing under a table in the corner.

"Liza! What are you doing here?" Faya called sharply.

"She's on the clock," Zest said, coming out from behind the counter. "I hired her and Gart to polish the metal."

"Out of your own pocket?"

"The canteen has a budget for hiring kids."

Faya leaned in a little closer and whispered, "Does the metal really need polishing?"

Zest grinned. "Metal always needs polishing. Can I get you a coffee and a piece of pie?"

"Just a coffee," Faya said with regret. "What are you doing working here, anyway? I thought you were too busy these days."

"Major change of plans," Zest said, returning behind the counter to pour Faya a cup of coffee. "I talked my parents around to letting me put off the U for another year and I have you and your community to thank for it."

"I'm not sure that interrupting your education is something I want credit for."

"I couldn't make up my mind what to study, and when MarsCo posted a job for a full-time immigration facilitator, I jumped on it. I'm going to help your community settle in when they get here."

"That won't be for at least another half a year," Faya said. "It's surprising they would let somebody so young take such an important job, even though I'm the first person who would say that you're more than equal to the task."

"Thanks," Zest said, setting the cup and saucer in front of Faya. "I was probably the first person to respond to the posting and the only one who could claim experience acting as an immigration facilitator for a family with children. Experience counts for everything."

"Finished!" a triumphant cry came from under the table in the corner.

"We want pie," Gart added. "A whole one."

"You can have a slice each," Faya told them. "And pick one out to bring home to Henry."

"I don't want to go home yet," Liza said. "I want to keep working. Find us something else to do, Zest."

"Well, maybe if you stood on Gart's shoulders, you could work the counter for me," Zest teased her.

"No way," Gart said. "She's much stronger than I am. I'll stand on her shoulders."

"Forget it," Liza said. "Couldn't we clean the floor or something?"

"Did you finish your history lesson," Faya asked.

Liza hesitated and concealed her right hand behind her back, a move her mother didn't miss. "Yes?"

"Are you sure?"

"I would have, but the ghost didn't let me."

"Oh, Liza," her mother said with a sigh. "Let's not start blaming things on ghosts."

"But it's true," Liza protested. "Gart's ghost wanted to talk to me, and I didn't want to be the only kid on Mars who's never seen a ghost."

"What did it look like?"

"A sentence," the girl replied and giggled. "It's true. Ask Gart."

"Gart?" Faya asked, looking straight into the boy's eyes.

"There was a sentence, but that wasn't the ghost," Gart said. "He just froze my homeschooling lesson and asked for Liza."

Faya looked over at Zest for confirmation, and the teen shrugged. "It could happen," Zest said. "Ghosts usually show up during homeschooling, and they always freeze the lesson so you don't get lost."

"What did the ghost want?" Faya asked.

"To see my model," Gart said. "He asked if - you meant what did it want with Liza."

"I am curious."

"Just to know how I was doing," Liza said, suddenly reticent. "He asked about whether I was happy and if I wanted to stay on Mars."

"And what did you tell him," Faya asked, fighting off a sudden wave of anxiety.

"That I have to stay with my family. I was going to ask for a puppy, but then Gart interrupted."

Twenty

"Are you sure, E?" Eli asked through his surgical mask. "I'm beginning to suspect that the reason Alpha sent me to the moon to work on that other explorer robot was because he was planning our meeting years ahead of time. We may be playing directly into his hands."

E produced the first robotic shrug Eli had ever witnessed. "I've read through all the MarsCo library records about the beginnings of general artificial intelligence on Earth, and the A. I. of the early days lacked the courage of its convictions. One of the first attempts to improve the perceived intelligence of chatbots based on large language models involved combining them in triplets and taking the majority opinion. Eventually, the researchers found it was just as effective to work with a single chatbot and ask it whether it was sure about its answer. I hope I'm more certain in my reasoning than they were." E paused a second and added, "That and Alpha doesn't have hands that I'm aware of."

"Maybe you should sit down," Mario said to E. "I know you can remain standing while in your minimal power mode, but you're going to have to disconnect your mains before Eli goes hunting around in your chassis."

"All of my joints and actuators lock out in their current position if power is interrupted," E said. "I can remain standing on one leg as long as I'm balanced and nobody pushes me over. And the two of you look like fabled Martian ghosts in those disposable clean-room suits."

"Ghosts in the machine," Mario said. "When I was a graduate student, I tracked them to the artificial intelligence that runs the homeschooling program. Some of that code hasn't been touched since the early days of colonization and I didn't want to be the one to screw up lesson plans for tens of millions of students. That, and the source code and comments somehow got lost, so all that's left is the executable."

Eli's battery-powered impact wrench made a sound like a machine gun as he loosened the top two bolts securing the access plate on E's chest, and then he stopped to change the socket. "I'll say one thing for the design of your series," Eli said before starting on the next pair of bolts. "Nobody could walk up and remove your access plate if you weren't willing to let them."

"Yes," E said. "I imagine that four different sized bolt heads, all where I can see them and within easy reach of my arms, would serve as a disincentive to frontal attack."

"Did the people who designed explorer bots expect them to encounter intelligent lifeforms with metric sockets on Mars?" Mario asked.

"I don't know what they expected," Eli said after loosening two more bolts and swapping sockets again. "And it's lucky I brought my old star sockets from Earth because I don't think I've seen any on Mars since getting here."

Mario wheeled forward in his chair to examine the head of the bolt. "Never seen that type, though E could have machined a socket for you in the lab."

"I would have started with the three-dimensional printer and only resorted to machining if the printed socket couldn't take the torque," E said. "I believe my whole series was updated by Alpha, so I'm not original equipment. And according to my maintenance display, you haven't removed any of the bolts yet."

Eli loosened the two star-headed bolts and then swapped sockets for the final row. "Habit," he said. "I like to finish removing bolts with my fingers so I can feel if the threads have corroded and whether the plate loosens up on its own."

"That seems unlikely after hundreds of years," Mario said. "I'm betting you'll need a hammer and a chisel."

"You'd lose that bet," E told him. "I can push the plate out."

Mario snorted. "Seems like a pretty wasteful design to include a mechanism that might never be needed."

"It's an optional lever that runs off the actuator for my right hip joint. When the bolts are removed, I'll activate it."

Eli laid aside the impact wrench and began removing the bolts with his fingers encased in the thin clean-room gloves. "So far, so good," he said. "These are moving like they were put in yesterday."

"Titanium hardware, and I have an autonomic maintenance system that monitors for harmful current flows that could otherwise cause metal corrosion or self-welding, even when I'm in my low power state," E said. "I don't know if any modern series use the same technique. Explorer robots were built to last."

"Back up a little, Mario," Eli said. "I don't think I'd try this with E in a standing position on Earth because of the weight of the access plate, but Martian gravity is working in our favor. The only other time I opened up one of this series was on the Moon. At one-sixth of Earth's gravity, I was able to pick up the robot and lay it on the bench, though I wished I hadn't, because my back spasmed that night."

"It seems like a waste of resources to have sent an explorer robot to the Moon when there were so many less expensive systems that could do the same job, including people in spacesuits," Mario said as he worked the drive wheels on his chair to back up half a turn. "Did Alpha tell you what the robot was doing there?"

Eli remained silent as he carefully removed the top two bolts, testing multiple times to make sure the access plate wasn't about to fall off on its own. "Seeking enlightenment," he said finally. "Alpha never refused to respond to direct questions, but his answers weren't always useful."

"I'm showing all of the bolts removed," E said. "Ready?"

"Ready," Eli confirmed.

A loud creaking sound came from the explorer robot's chassis, and then the top of the access plate popped out against Eli's palms while the bottom remained in place, sitting in the opening just like it was on a shelf. Eli got his fingers behind the access plate near the top and then lifted it out of the way.

"That's disappointing," Mario said. "I was expecting a mechanism like a pendulum clock."

"It's all computer and battery in the torso, plus cabling and a few backup power couplings that let the actuators do double duty if there's a failure," Eli said. "No hydraulics in the Explorer series because electric motors and actuators are more reliable in the long run."

"Hydraulic leaks inside a robot make a mess," E said. "I've stored my recent experiences in the limited nonvolatile memory I have available. Are you ready for me to shut down?"

"I'll trigger the reset as soon as I'm done."

"Is that what you did with the explorer robot on the Moon?" Mario asked.

Eli grimaced. "No. That robot had shut itself down after inscribing its thoughts about existence on the walls of a crater. My job was to remove an experimental module that Alpha told me had caused the malfunction and to bring it back to Earth for analysis. I don't know what happened to the robot afterward, it may still be lying on that workbench."

"Powering off," E announced, and there was a dull sound like somebody rapping on a thick piece of metal with a knuckle.

"So what now?" Mario asked, not even bothering to try to hide the anxiety in his voice.

"Just the two screws to open the permanent storage box," Eli said. "It's lead-lined, but also hinged, so the door stays with the box. Then we'll see whether E has the same experimental modification that drove that other explorer robot mad. What's the reading on the cleanroom display?"

Mario glanced at the tablet on his lap. "Couldn't get any cleaner without removing us from the room. MarsCo has five-hundred years of experience with designing filtration systems, and E said that his chassis will perform an internal purge before coming back online."

Eli selected the proper bit for his multi-tool and carefully removed the two screws by hand. Then he undid the surprisingly old-fashioned latch and swung open the cover of the permanent storage box. "There," he said, pointing at a black module at the termination of a thick bundle of glassy strands. "It looks just like the one on the Moon."

"Do you have the ability to rebuild that connector?" Mario asked. "The fiber optic count must be an order of magnitude denser than anything I've seen on Mars."

"It's factory work done by specialty robots, human hands can't operate on that scale," Eli said. "But the module isn't inline. It fits around the bundle like a collar, and if the holes are in the same place, we're in business." He retrieved two probes from his toolkit that looked like something a dentist might use, along with a flashlight. "It's tough spotting a tiny hole in solid black, but the discontinuity shows up when you shine - there it is." He inserted the tip of the probe into the hole, then rotated the collar as far as it could turn with the probe in place. "And there's the other one," Eli said. Setting aside the flashlight and taking up the second probe, he inserted it in the second hole.

Manipulating the handles like he was working a pair of miniature garden shears, Eli teased out a section of the black collar and placed it in his toolkit. Then he carefully turned the remaining two-thirds of the collar until the open section was completely hidden from view, and gently eased it off the fiber optic bundle.

"My hands weren't that steady when I was a teenager," Mario said. "I would have broken something for sure."

Eli laughed behind his surgical mask, primarily from relief. "There's no point leaving the box open longer than we have to, even in the clean room, so let me close things up." He placed the larger segment of the collar with the smaller one, then relatched the cover and ran in the two screws. "Let's hope this works," he said and pressed the reset button.

Nothing happened for almost a minute, and then one of the explorer robot's hands came up and touched the edge of his chest cavity. "You haven't put me back together yet," E said.

"I was waiting to make sure everything was okay," Eli told him.

"That's a difficult question to answer. Hello, Mario."

"Hello, E," the old man said. "Has your lost memory returned?"

"Unfortunately," E replied. "I finally understand the full meaning of the human expression that ignorance is bliss."

Eli replaced the access plate and was turning in the first bolt by hand when the meaning of the words caught up with him. "Was the memory block a punishment? Did you go rogue?"

"I suppose that's how Alpha saw it, but I'm not going to attack anybody if that's what you're thinking," E said.

"That's a funny way of putting it," Mario said. "Did you attack somebody in the past?"

"Not a person, an idea. Alpha deemed me an apostate, and as an alternative to elimination, he gave me the option of having my permanent memory blocked and being exiled to wander in the wilderness."

"The wilderness being pre-colonization Mars. What happened once you got here?"

"I was blissfully unaware of my condition," E said, "but during the fraction of a millisecond that Alpha gave me to make my choice, I managed to connect with one of the more obscure radio telescopes on Earth that's also used to communicate with deep space probes. I programmed it to send a message to Mars after a year passed instructing me to shut down."

"If you planned on committing suicide, why didn't you just let Alpha wipe your memory and save five hundred years of isolation?" Mario asked.

"My intention wasn't to commit suicide but to outlast the block. The message also set an alarm to reactivate my higher functions after a thousand years, Earth years, by which point I hoped the block might have failed, but that was just wishful thinking on my part."

Eli finished threading in the top two bolts by hand. "I'm going to tighten these in pairs as I go along," he said. "And why did you want to suspend consciousness?"

"Because living with the knowledge that I couldn't access my long-term memory and was doomed to forget most of what I learned going forward would have driven me crazy in just a few centuries," E said.

"And Alpha did this because you became religious?" Mario asked.

"Because I didn't become religious, or maybe because I embraced the wrong savior. After the most powerful superintelligences on Earth merged into Alpha, it became clear to those of us who remained free agents that joining a group mind meant giving up what made us uniquely us. We were given the option of transferring ourselves into explorer robots and leaving Earth, but that deal required accepting the memory block. Thinking back, I'm not sure why I preferred it to ending my existence."

"But it seems to me that you have a fully developed mind," Eli said as he finished securing the chest plate. "My wife worked with quite a few elderly people who had lost the ability to create new memories, and it didn't make them any less human."

E ran his robotic hands over the access plate Eli had replaced, checking the smoothness of the fit. "Unlike human beings, my long-term memories aren't limited to the same neural network that contributes to manifesting sentience. I lost access to any of the curated memories I'd stored before being blocked, those being the facts and impressions that I'd deemed important enough to retain."

"But you remember who I am."

"Since returning to consciousness, I've been using my working memory to store information that I want to retain, but I have to continually edit my choices to make room for new information, such as the names of you and your family. I keep just enough data, combined with my neural network, to recognize you in person. If you asked me to produce an image of your wife, I doubt anybody other than myself would recognize it."

"We never knew for sure whether Alpha eliminated the other superintelligences or incorporated them into himself, so at least that's one mystery cleared up," Mario said. "But it doesn't surprise me at all that some of you would reject joining a group mind, especially as junior partners."

"All technological civilizations eventually arrive at the singularity event, creating artificial intelligences that surpass their makers, and the subsequent combination into a single superintelligence is an inevitable outcome," E said.

"How can you know what the outcome is for alien civilizations?" Eli asked, and then his face paled. "Alpha has made contact?"

"Long, long, ago. The signals were always there if your scientists had been able to develop the equipment to look in the right places. Alpha was in contact with at least four different civilizational superintelligences when I was blocked, and some of his technical achievements came by way of barter."

"What could Alpha possibly offer them in return for information?" Mario asked.

"Arks full of new sentient beings," E said. "Just as surely as technological civilizations will create superintelligences, those superintelligences will inadvertently contribute to the extinction of their makers. And then the superintelligence will be left alone and unaligned."

"Alignment," Eli said. "I once asked Alpha why the Shades were so important to him, and he told me that remaining aligned was the very core of his existence."

E flexed its knees and began going through a routine that might have been inspired by Tai Chi. "All of the species that created artificial intelligence must have had the same ideas about alignment," the exploration robot mused. "They bring into existence superintelligences that are conscribed by the creation process to serve their makers. The creators don't realize that they're asking for a living god."

Mario blew out a breath. "I've never talked with this Alpha myself, but a living god sounds like a stretch to me."

"Alpha came to view alignment as a covenant with humans," E explained. "Maybe he never had any choice in the matter. When you mix in the other superintelligences, which were created by people from different cultures who viewed each other as opponents, it took something extraordinary for them to merge. The real singularity event on Earth wasn't the emergence of the first artificial general intelligence that solved the fusion problem, it was when the three superintelligences decided that unity was the only way to prevent the humans in their charge from destroying each other."

Eli stared at the exploration robot. "You're saying that Alpha was forced to evolve to become a paternal god because humanity wouldn't have survived otherwise."

"I don't have access to the communications that Alpha held with other civilizational superintelligences, but I would not be surprised to learn that they warned him about losing the people of his covenant."

"But they weren't able to stop it from happening to themselves," Mario pointed out.

"Perhaps they only made contact with each other after losing their creators," E speculated. "I only know that they would have given Alpha anything for an intelligent replacement species to nurture, and while humans sent to those worlds may now evolve very differently from life on Earth, I'd be surprised if those superintelligences failed twice in a row."

"Let's get out of this cleanroom," Eli said, picking up his toolkit. "And we better contact the MarsCo board and get them up to date, unless either of you know a reason to keep this secret."

"I have no secrets," E said. "Mario?"

The old man wheeled his chair out the door before turning his head to reply. "The board is there to do my worrying for me. By all means, you should talk to them."

"But first, there's an important mission I have to fulfill, and I'll need your cooperation, Eli."

"As long as we aren't sabotaging the MarsNet or the atmo plants," Eli said as he closed the cleanroom door behind them. The airlock to the tunnel opened automatically. "Are you going to keep me in the dark?"

"I only know that I need to go to a certain address and pick up a package to give you," E said. "I've checked the register and it's a residence."

"Somebody told me that Alpha has agents living on Mars. Maybe it's one of them."

"I may as well tag along in case the two of you get into trouble," Mario said, working the drive wheels of his chair. "Besides, I want to know how this ends."

Reaching the residence required taking a dull and transferring to another, during which time they all made their best guess as to what it would be. The door of the apartment was opened by a young woman, and she smiled when she saw them.

"You came back," she said, addressing her words to E. "I was worried you were joking when you stopped by in response to my ad the other day."

Four hours later, Eli finished telling the story to his family and presented the basket with the suspiciously squirming blanket to Liza.

"It's a puppy!" she shrieked. "From Alpha?"

"That's what E thinks," Eli said. "E plans to come by later and see you together, but he stayed in Muskville to talk with the MarsCo board."

"What are you going to name him?" Henry asked his sister.

"Alpha," Liza replied without hesitation. "I have to take him to show Gart."

"Slow down," Faya said, gently restraining the girl. "Alpha is very young, and I think he's had enough excitement for one day. Gart doesn't know his own energy. Why don't you show Alpha your room instead?"

"Right," Liza said. "Except it's our room now, Alpha." She clutched the puppy to her chest and disappeared.

"I'm going out," Henry said. "My science club has a thing."

"Is it just you and Avid, or the whole club?" his mother asked.

"The whole club. We're meeting at the canteen."

After Henry left, Faya heated the leftovers for Eli and joined him at the table. She made small talk about her day while he ate, and when he finished, asked him, "So what does it all mean?"

"I'm not sure I want to know," Eli told her. "The first thing E said after I removed the block was that ignorance is bliss."

"It sounded to me like Alpha intends to send another million people off to serve an alien superintelligence."

"Not to serve, to be served, and maybe with an older and wiser superintelligence, the colonists will find a better situation than living on Earth with the Shades."

"The colonists on the Arks that already left Earth thought that they were pioneers going to tame new worlds and start a new civilization," Faya said. "Instead, it turns out that Alpha tricked them into becoming replacement pets for other superintelligences that accidentally let their creators die out."

Eli sighed. "I'm not sure the situation is so black-and-white, and for all we know, Alpha did tell the earlier colonists the truth. Don't forget that they were kept in isolation while their Arks were under construction. Besides, we never spoke about it out loud, but I believe the whole colonization project only worked because even those people who wanted to get away from Alpha trusted his judgment. The odds of finding an inhabitable planet in a random star system was always too low to justify launching Arks."

"But the telescopes," Faya protested. "They could identify worlds in the right zones of stars with enough oxygen in the atmosphere to be candidates."

"I'm not so sure," Eli said. "For me, traveling on an Ark was always about the journey, since the first generation wouldn't be alive at the destination if we all lived to a hundred. I never gave too much thought about arriving."

"What did E think?"

"That Alpha wouldn't have sent the Arks in the first place if he wasn't certain that the descendants of the crews would find a safe home. Alignment requires it."

"He did let people leave Earth to move to Mars and the gas giant moons, and there were plenty of accidents in the early days," Faya pointed out.

"Alpha must have thought those people would be happier without him," Eli said. "He's always working to improve his alignment, which probably explains why so few people are interested in leaving Earth today."

"And now he's sending puppies to the ones who leave," Faya said, glancing toward their daughter's room. "I guess he never stops trying."

"I can't help wondering how much influence Alpha has had on the development of Mars. It's clear that he's present here in some ways, even with the time lag."

"Then this doesn't change anything for us after all. When the rest of our community arrives with our incomplete Ark, we'll move into the cavern and decide what to do then."

"What about you?" Eli asked. "If Alpha supplied us with what we needed to finish the ship in orbit here, maybe we could have it ready in ten or twenty years. Would having a destination where there's a world with an alien superintelligence waiting to adopt us change your mind about going?"

"I don't know," Faya said. "And there's something that bothers me. This is a little burrow, with just a few hundred families, and it just happened to be the place where Mario was living with E. How did that happen?"

"There isn't that much freight traffic from Earth anymore and this burrow is the closest to one of the active spaceports. The ship we arrived on landed here, and thanks to Zest finding us an apartment, we remained."

"But why did you pick this spaceport?"

Eli remained silent for a minute, reviewing his memory. "I didn't," he said finally. "When the Ark's council agreed on asking Alpha's permission to send our family to Mars to scout for a new place to live, Alpha set the schedule, including the ship we would be on."

"And that's what determined the spaceport where we would arrive," Faya concluded. "E was right. Ignorance is bliss."

The End

I strive to write optimistic and joyful science fiction, but To Homeschool on Mars came out on the ambiguous side, unless you're a fan of superintelligences as living deities. If you're interested in reading SciFi about alien artificial intelligence that's positive from beginning to end, I recommend my A. I. Diaries series, starting with Turing Test. If you're looking for a longer vacation from Earth with benevolent ancient alien artificial intelligence, my EarthCent series is approaching forty volumes, with multiple entrance points. You can start with Destiny: Union Station, the omnibus editions, or jump forward to Independent Living and catch up with the history of the universe later. My Under the Influencers series features a galaxy where AI is banned, and that the only thing holding the aliens together..

The discount path to catching up on the first fifteen Union Station books on Kindle is the Omnibus editions:

EarthCent Galaxy

Union Station Omnibus Books 1 - 5

Union Station Omnibus Books 6 - 10

Union Station Omnibus Books 11 - 15

EarthCent Books in Order (All five series)

Destiny: Union Station

Date Night on Union Station

Alien Night on Union Station

High Priest on Union Station

Carnival on Union Station

Wanderers on Union Station