Building Harlequin's Moon

by Larry Niven

“We looked . . . the High Council looked at the problem,” Gabriel said carefully, “and the Astronaut program verifies. To build an antimatter generator, we need manpower. We’d have to warm half the ship. The garden wouldn’t feed them or recycle enough air, and we don’t have the room either. They’d use up all our resources. We’d die. “Second possibility is to build habitats like the asteroid civilizations in Sol system. What’s wrong with that?” Wayne snorted, though he knew he was being tested. “The Belt cities needed too much Artificial Intelligence, too much nanotech, too much of everything we’re running away from. AIs wound up running it all.” Gabriel nodded. “So we can’t do that. And we could build nanos and let them build a collider and run it for antimatter, with Astronaut running it all. Only we deliberately forgot most of what we need to build tailored nanotech, and Astronaut is another AI. By now it looks like Earth and Sol really have gone down the recycler, and if it wasn’t the AIs taking over, it must have been nanos turning everything to sludge. At any rate, Sol system isn’t talking.

Andrew shot a hard look at Rachel. It’s not my fault! Rachel felt anger mix with her anxiety. Would Gabriel fail them all because of Andrew? Harry and Ursula weren’t even involved! She looked around. Ursula’s hand covered her mouth, her eyes watching Rachel instead of Andrew. Harry was stoic, not looking at any of them. He must have felt Rachel’s eyes on him, because he turned and blurted out, “Andrew, apologize!”

“Ali helped too.” He sighed. Time to teach. They only knew part of the story. “There wasn’t any Selene when we came here. There was an oversized gas giant planet, Harlequin, and almost a hundred moons. We picked a big moon for a foundation. It had no spin—no day or night with reference to Harlequin. We made that, hitting it over and over in the same place, from the same angle, making tilt and spin. Days and seasons. Building Selene. Then we—went—cold—for a long time, to let the whole system stabilize and cool. “We woke up to a pockmarked ball covered in regolith. There was a little ice, a few small pockets of underground water, and the beginnings of an atmosphere, but humans need lots of easy-to-reach water, and thick atmosphere to shield us from space. So we brought in comets. Then we

went cold again. Then we brought in more comets. The comets gave us the water you see here.” “So the water is from space?” Rachel asked. “Isn’t everything? This deep sea is the motor that drives Selene’s hydrology. We need this much water for the humidity to grow tropical plants rather than cactus. But we had to contain most of the water to limit the effect of the tides, which are worse here than on Earth, because of Harlequin.” He pointed at the gas giant, which hung just off center in the sky. “Gravity pulls the water toward Harlequin. If we didn’t contain it, Selene would be flooded with every high tide. We could have made hundreds of small seas instead of what we did make; the Hammered Sea and Erika’s Folly, but they would have been harder to manage. Oh, lots of craters have a little water in them, but over half our water is right here.” He paused, and said, “Besides, I wanted to make a real sea.” That made him feel

giddy still: to build a sea because he wanted to! “Feel the damp wind on your face, Rachel?” She nodded, holding her arms over the sea below them. “It blows up the crater walls, carrying water vapor. It’s cooler than the air it meets on the far side. It would stay inside the crater and rain here, except we’ve built paths for it to funnel through. So we drive the rain to fall mostly outside the Hammered Sea, where it fills streams. We have pumps that take care of it when Selene doesn’t, a backup system that sends water through the crater walls to fill the streams. We used the out-pumps a lot, early on. But we haven’t had to use them for years—we test them every month, but I dun...

“We have observation satellites and cameras and pods and other ways to collect data and information. We have to monitor what happens down here. Surely you understand how much information we need to monitor all this?” He spread his arms wide, and then pointed at her. “You yourself gather information from your trees.” Rachel blushed. Of course she knew about the cams. What had they seen? Was it really private even under the canopy of trees in the grove? Could they hear conversation as well as see people? Did he know about her helping Ursula so much while they were gone the last time? What must the ship be like if they could see so much? Did they spy on each other this way?

Gabriel talked about Rachel often, and Astronaut was pleased to see her. It looked for a way to make contact. She wore a wrist pad, but her direct Library access was blocked. She had no built-in data linkages. This was a new thing. Every other human aboard John Glenn was linked to the Library, to places where Astronaut was also linked; everyone belonged to the vast web of ship information. It watched what they queried and what they did, and overheard their conversations with each other. Access was possible from Selene. Why didn’t Rachel have access? Did any of the Moon Born have access?

Presently it knew that Rachel was a slave.

“Not exactly. You are . . . let me try again. We limit the kinds of tools we use. Certain things need to be done by humans. We could have shaped Selene with nothing but machines, but we would have had to use machines smarter than we wanted them to be. Machines that are too smart are dangerous.”

“There are two hundred Council. We are collectively responsible for the ship. We financed it—” Kyu shook her head. “Sorry—we made it possible to build John Glenn. We planned this trip. Five of us are High Council, and have ultimate responsibility for everyone. There are a lot of Colonists—people picked to come because they have specific knowledge we will need when we get to Ymir. And we can’t afford to wake them all up here—we’ll need them on Ymir. It would be horrible to risk everyone from Earth someplace as dangerous as Selene when we’ll need their-genes and Earth-educated minds more later.” Rachel swallowed. “So you risk us instead?”

Kyu ignored his last comment. “Rachel is an experiment. If we don’t like how she reacts, we’ll try something else with someone else.” “If they know too much, they’ll realize exactly what we’re doing to them.”

“Hell . . . it means we’re scared. We’re afraid of the little machines.” Gabriel grimaced. “We keep nano confined so it won’t get loose. It does things to your body, it fixes damage inside your cells, but it doesn’t do anything we don’t program it to do. It doesn’t rebuild your skull and brain, or line your knee joints with carbon fibers, or build a better kidney, or any of the craziness—” He made himself stop talking. Then, “if we can keep it docile, it keeps us from dying.

“Who do you have to turn to now?” Treesa prodded. “G-Gabriel.” “Who has power over you?” Treesa cracked her knuckles and ran her fingers through her hair. “Council, but they always had the power. They’ve always had all of the power.” “So tell me this. Do they have more power now, or less? I mean, over you.” “I don’t understand. They have it all. I don’t have any choices, and they just stole the one choice I wanted to make—to be with Harry.”

“I am an intelligence that isn’t human. Not a machine—a system based on information. Like you are based on biology. I live in a machine like you live in meat.” Almost everybody except Gabriel acted afraid of Astronaut. Liren, and Ali, and perhaps Kyu, at least a little. Rachel’s stomach fluttered. She was talking to someone the Council feared. “Why do you want to talk to me?” “You interest me. You are a slave for the Council, like I am. You and I share some of their goals. Any other choice would be death. But some of our individual goals, mine and yours, are different from Council’s goals. So we have some of the same problems.”

“We are both bound by Council rules. You have to ask me questions. That’s how the rules work for me. Treesa can help you. If you ask broad questions, I can find much that is related to the question.”

It’s all aggravated because the rules for the Earth Born are different from the ones for the Moon Born. Before you left, it wasn’t that way.”

At midnight she woke up sweating, knowing she could never trust Gabriel so much again. She was dancing to more strings than just his, and he was a puppet too. Liren and Kyu and the captain, they all had more power than Gabriel. Treesa and Astronaut made a difference too, although Rachel didn’t understand it yet. She had thought Council all saw things the same way. But they argued and schemed and planned different plans inside the big plan that they all supported—to leave Selene. Gabriel was asking Rachel to help with that plan, but she didn’t want Council to leave.

“People—Earth Born largely, but Council too—they treat us like—like badly built machinery. Being Moon Born is a curse. It makes me wonder, how will things work when there are even more of us here? Will we always just do what you say?”

like yesterday for me. It was only eight years ago, as far as I remember. The sixty thousand years in between was ice time for me, and so I still remember how the AIs ran things, how people died right and left. Or got locked up. My older sister disappeared and never came back. They took her for ‘attempting to destroy an intelligence.’ I have no idea what she did, and neither did my parents. That’s why we came here—why we left.

“We take orders from Council. We all do. We’re alive because of them; we got away because they financed this trip. Imagine you got an order to go live someplace you hated, and to share your bed with a man you didn’t know, who didn’t share any of your experiences or history. Your dad was only nineteen when they contracted us—younger than you are now. And I was thirty. I was awake—thawed—in the wrong place, separated from everyone I loved by too many years to count.

“They ordered us to contract. They ordered us to have children. I didn’t want to. I wasn’t ready. There was supposed to be a new world waiting for me. A place where we could be truly human, could build a home, like Earth, but where we didn’t have to make the same mistakes. We’d learned. We know . . . how dangerous the toys we make can be. That’s what it all was at first, stuff that did anything we told it to . . . until our creations outgrew us. Instead of waking at Ymir, a new paradise, I woke to a pitted moon! It’s nothing like Earth, Selene. It’s a struggling and sickly garden in a harsh place. Nothing to do—no proper games, no 3D video, no social life, no universities, nothing. We left the technology we loved too . . . of course. “I hated being ordered around. But we’re alive because of Council. We signed on without any rights. There’s a contract we all signed . . .” Kristin stopped for a minute, took a drink of juice. Rachel said, “You’re enslaved.”

Rachel was quiet for a long time. “You’re right. I’m not convinced. But we mattered during the fire. They needed us. We’ll have other chances to prove ourselves.” She sat down and looked him in the eye. “So yes, I’m afraid they will leave. I’m sure they want to leave. But I am convinced we can’t fight them directly. We have to find other ways. Tell you what, you agree to stay away from anything violent, and to stop making people angry with Council, and I’ll agree not to hinder you. If I want to argue with you, I’ll do it in private, like this.” He would understand she expected reciprocation. “But I won’t agree to anything destructive, and I won’t break Council rules. I am helping to build Selene, and I will not help you destroy it.

Rachel spun and looked at him, her jaw tight. “We need more to do—not less. We need responsibility. We need to learn so we can help ourselves. We’re getting angry, Gabriel. What are we working for? So you can leave? And that’s what you want me to help you with?”

“What do you think we’re building Refuge for? It’s taken time away from the collider.” He tried to put himself in her place. What would he want, if he were Rachel? “Maybe some of you can go with us. It’s pretty clear some of the Earth Born will stay. Selene is stable enough that its atmosphere will last for a century or more. We didn’t have a hell of a lot of choices.” “Why don’t you stay?” “We may be the last humans in the universe. I don’t know. With luck, there is an established colony at Ymir, and we can add to its chance for survival. The issue is bigger than either of us. And you won’t all fit aboard John Glenn.” He didn’t know why he was being so candid with her. Maybe because she asked so directly, and she deserved better answers than the Children got from most Council? She said, “You want to know if I’m happy? Well, my home—Selene—it will die someday. Its atmosphere is destined to bleed away, and your skills are the main thread that keeps it going. You’re leaving. And you already told me there’s nothing aboard John Glenn we can rebuild to use as an intersystem starship, to follow you to Ymir. Even if I die before a fire kills us all, or a flare, or quakes, I’m afraid to have children of my own.” Gabriel cringed inwardly. Council had talked of sterilizing the Children when they left, so they could live their lives in full, leaving Selene naturally empty before its air became too thin to breathe. There was no final decision.

“Of course I care,” he said evenly. “But, Rachel, the whole reason for Selene is the collider. I want to see John Glenn leave. I came from Earth; I know why we have to go on. I’ll stay here, stay with my kids, I’ll die here, but John Glenn does need to join the rest of mankind.”

“If we make our antimatter and fly away—then everyone left on Selene will die. Maybe not right away, maybe not for generations, but if we stayed we could keep the environment going longer. We haven’t given them the technology to live on an unstable moon. You know that, I know you do.” Gabriel frowned. “None of our choices were good. We can’t fight our own rules and laws, we can’t kill our own people, or use interdicted technology—without risking the death of us all! We cannot fight among ourselves. It would be the perfect joke for the only humans in quintillions of klicks to kill each other.”

Of course she misunderstood. “Rachel, antimatter containment is a technique hundreds of years old. We know how to do it.” Ali got back up and sat down at the table. “Treesa and I told her that too.” Ali turned her cup around and around in her hand, nervous. “And we were wrong.” She tugged on her braid, sighed, and then put her hand over Gabriel’s hand. “We made Selene, Gabriel, but Selene isn’t our home. John Glenn is. And maybe, someday, Ymir. But Selene is Rachel’s home. We didn’t hear that when she said it; we didn’t understand. She sees our choices as being willing to risk her home, as not caring.”

“Let’s say different. You were trying to save the people for Ymir. Well, we were trying to save Selene for the Moon Born. We don’t have room for all the Moon Born, can’t take them all to Ymir any more than I can get my fiancé back from Leif Eriksson. There are some things that aren’t possible. But it is possible to make a better deal than we have.”

If you leave the way you plan, you will give us death. Which would be a loss for you. Maybe not much loss to those of you who have never been on Selene. But for these people, for my friends and counselors here, it would be a loss. A death. You can give us life, hope, even after you leave.” Her hands shook and she clenched her fists, digging her nails into her palm. “It means that you must lose some of your fear.

“There are three things we want—and if you give them to us, I think you will leave for Ymir with clean hands. First, it will take technology to leave Selene habitable. Help us learn the skills we need to stand a chance of living here long enough to build a real civilization. I’ve studied Earth before the AI disasters, before the horrors that set you running. Perhaps different choices can be made. We will try to make

good choices; to learn from mistakes made in Sol system. If we fail”—she shrugged for emphasis—”if we fail, we are isolated here anyway.” There was silence all around her. Silence from the ship. Rachel licked her lips. “Second, build Gabriel’s flare kite. You turned it down once, because it would take too long, too many resources. You have the resources. Give them to us, share them, so that we are free to live without fear of flares. “Third, generate your antimatter entirely outside of Harlequin’s moon system.” To Rachel’s surprise, Erika raised a hand, gesturing to Rachel to continue. Her face was unreadable, intense, focused tightly on Rachel. Rachel spoke directly to Erika. She was the power here. “We would not try to change your dream. I thought that was what I wanted; to keep you here, keep you prisoners in Apollo system. That is an unacceptable choice to you. There are choices unacceptable to us. We must have a voice in what you do with our world, in what you do here. We cannot allow—and yes, you can kill us all and start over—but we cannot allow antimatter to be made here. I don’t believe you would do that. We are your children, as well as the Children of Selene.