“You’re going to stay,” he said.

The silence lasted three heartbeats. Four. Five.

“It’s arranged,” Basia said.

Prax hit him. He didn’t plan it, didn’t intend it. His arm rolled through the shoulder, balled fist shooting out of its own accord. His knuckles sank into the flesh of Basia’s cheek, snapping his head to the side and rocking him back. The big man boiled across the room at him. The first blow hit just below Prax’s collarbone, pushing him back, the next one was to his ribs, and the one after that. Prax felt his chair slide out from under him, and he was falling slowly in the low g but unable to get his feet beneath him. Prax swung wild, kicked out. He felt his foot connect with something, but he couldn’t tell if it was the table or Basia.

He hit the floor, and Basia’s foot came down on his solar plexus. The world went bright, shimmering, and painful. Somewhere a long way away, a woman was shouting. He couldn’t make out the words. And then, slowly, he could.

He’s not right. He lost a baby too. He’s not right.

Prax rolled over, forced himself up to his knees. There was blood on his chin he was pretty sure came from him. No one else there was bleeding. Basia stood by the table, hands in fists, nostrils flared, breath fast. The daughter stood in front of him, interposed between her enraged father and Prax. All he could really see of her was her ass and her ponytail and her hands, flat out at her father in the universal gesture for stop. She was saving his life.

“You’d be better off gone, brother,” Basia said.

“Okay,” Prax said.

He got to his feet slowly and stumbled to the door, still not quite breathing right. He let himself out.

The secret of closed-system botanical collapse was this: It’s not the thing that breaks you need to watch out for. It’s the cascade. The first time he’d lost a whole crop of G. kenon, it had been from a fungus that didn’t hurt soybeans at all. The spores had probably come in with a shipment of ladybugs. The fungus took hold in the hydroponic system, merrily taking up nutrients that weren’t meant for it and altering the pH. That weakened the bacteria Prax had been using to fix nitrogen to the point that they were vulnerable to a phage that wouldn’t have been able to take them out otherwise. The nitrogen balance of the system got out of whack. By the time the bacteria recovered to their initial population, the soybeans were yellow, limp, and past repair.

That was the metaphor he used when he thought about Mei and her immune system. The problem was tiny, really. A mutant allele produced a protein that folded left instead of right. A few base pairs’ difference. But that protein catalyzed a critical step in signal transduction to the T cells. She could have all the parts of an immune system standing ready to fight off a pathogen, but without twice-daily doses of an artificial catalyzing agent, the alarm would never sound. Myers-Skelton Premature Immunosenescence they called it, and the preliminary studies still hadn’t even been able to tell if it was more common outside the well of Earth because of an unknown low-g effect or just the high radiation levels increasing mutations rates generally. It didn’t matter. However she’d gotten there, Mei had developed a massive spinal infection when she was four months old. If they’d been anywhere else in the outer planets, she’d have died of it. But everyone came to Ganymede to gestate, so the child health research all happened there. When Dr. Strickland saw her, he knew what he was looking at, and he held back the cascade.

Prax walked down the corridors toward home. His jaw was swelling. He didn’t remember being hit in the jaw, but it was swelling, and it hurt. His ribs had a sharp pain on the left that hurt if he breathed in too deep, so he kept his breath shallow. He stopped at one of the parks, scrounging a few leaves for dinner. He paused at a large stand of Epipremnum aureum. The wide spade-shaped leaves looked wrong. They were still green, but thicker, and with a golden undertone. Someone had put distilled water in the hydroponic supply instead of the mineral-rich solution long-stability hydroponics needed. They could get away with it for another week. Maybe two. Then the air-recycling plants would start to die, and by the time that happened, the cascade would be too far gone to stop. And if they couldn’t get the right water to the plants, he couldn’t imagine they’d be able to set all the mechanical air recyclers going. Someone was going to have to do something about that.

Someone else.

In his rooms, his one small G. kenon held its fronds up to the light. Without any particular conscious thought, he put his finger in the soil, testing it. The rich scent of well-balanced soil was like incense. It was doing pretty well, all things considered. He glanced at the time stamp on his hand terminal. Three hours had passed since he’d come home. His jaw had gone past aching into a kind of constantly rediscovered pain.

Without her medicine, the normal flora of her digestive system would start overgrowing. The bacteria that normally lived benignly in her mouth and throat would rise against her. After two weeks, maybe she wouldn’t be dead. But even in the best case, she’d be so sick that bringing her back would be problematic.

It was a war. Kids died in wars. It was a cascade. He coughed, and the pain was immense and it was still better than thinking. He needed to go. To get out. Ganymede was dying around him. He wasn’t going to do Mei any good. She was gone. His baby girl was gone.

Crying hurt worse than coughing.

He didn’t sleep so much as lose consciousness. When he woke, his jaw was swollen badly enough that it clicked when he opened his mouth too wide. His ribs felt a degree better. He sat on the edge of his bed, head in his hands.

He’d go to the port. He’d go to Basia and apologize and ask to go along. Get out of the Jovian system entirely. Go someplace and start over without his past. Without his failed marriage and shattered work. Without Mei.

He switched to a slightly less dirty shirt. Swabbed his armpits with a damp cloth. Combed his hair back. He’d failed. It was pointless. He had to come to terms with the loss and move on. And maybe someday he would.

He checked his hand terminal. That day was checking the Martian body drop, walking the parks, checking with Dr. Astrigan, and then a list of five brothels he hadn’t been to, where he could ask after the illicit pleasures of pedophilia, hopefully without being gutted by some right-thinking, civic-minded thug. Thugs had children too. Some probably loved them. With a sigh, he keyed in a new entry: MINERALIZE PARK WATER. He’d need to find someone with physical plant access codes. Maybe security could help with that at least.