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.

And maybe, somewhere along the way, he’d find Mei.

There was still hope.

Chapter Eight: Bobbie

The Harman Dae-Jung was a Donnager-class dreadnought, half a kilometer in length, and a quarter million tons dry weight. Her interior docking bay was large enough to hold four frigate-class escort ships and a variety of lighter shuttles and repair craft. Currently, it held only two ships: the large and almost opulent shuttle that had ferried the Martian ambassadors and state officials up for the flight to Earth, and the smaller and more functional Navy shuttle Bobbie had ridden up from Ganymede.

Bobbie was using the empty space to jog.

The Dae-Jung’s captain was being pressured by the diplomats to get them to Earth as quickly as possible, so the ship was running at a near-constant one g acceleration. While this made most of the Martian civilians uncomfortable, it suited Bobbie just fine. The corps trained at high g all the time and did lengthy endurance drills at one g at least once a month. No one ever said it was to prepare for the possibility of having to fight a ground war on Earth. No one had to.

Her recent tour on Ganymede hadn’t allowed her to get in any high-g exercise, and the long trip to Earth seemed like an excellent opportunity to get back into shape. The last thing she wanted was to appear weak to the natives.

“Anything you can do I can do better,” she sang to herself in a breathless falsetto as she ran. “I can do anything better than you.”

She gave her wristwatch a quick glance. Two hours. At her current leisurely pace, that meant twelve miles. Push for twenty? How many people on Earth regularly ran for twenty miles? Martian propaganda would have her believe that half of the people on Earth didn’t even have jobs. They just lived off the government dole and spent their meager allowances on drugs and stim parlors. But probably some of them could run for twenty miles. She’d bet Snoopy and his gang of Earther marines could have run twenty miles, the way they were running from—

“Anything you can do I can do better,” she sang, then concentrated on nothing but the sound of her shoes slapping on the metal deck.

She didn’t see the yeoman enter the docking bay, so when he called out to her, she twisted in surprise and tripped over her own feet, catching herself with her left hand just before she would have dashed her brains out on the deck. She felt something pop in her wrist, and her right knee bounced painfully off the floor as she rolled to absorb the impact.