“If you pick this gun up right now, point it at a bad guy, pull the trigger, does it go bang? You just watched me put it together. Dangerous or safe?”
Prax opened his mouth, then closed it. An ache just behind his sternum grew a notch worse. Amos started to put the gun down.
“Safe,” Prax said.
“You sure about that, Doc?”
“You didn’t put any bullets in it. It’s safe.”
“You’re sure?”
“Yes.”
Amos frowned at the gun.
“Well, yeah, that’s right,” he said. “But you’re still not going.”
Voices came from the narrow hallway from the airlock. Jim Holden’s voice wasn’t what Prax had thought it would be. He’d expected him to be serious, grave. Instead, even during the times like now, when the distress clipped his vowels short and tightened his voice, there was a lightness to him. The woman’s voice — Naomi, not Cassandra—wasn’t deeper, but it was darker.
“Those are the numbers,” she said.
“They’re wrong,” Holden said, ducking into the mess. “They’ve got to be wrong. It doesn’t make sense.”
“What’s the word, Cap’n?” Amos asked.
“Security’s not going to be any use,” Holden said. “The locals are stretched too thin trying to keep the place from straight-out catastrophe.”
“Which is why maybe we shouldn’t be going in with guns drawn,” Naomi said.
“Please, can we not have that conversation again right now?”
Her mouth hardened and Amos pointedly looked at the gun, polishing the parts that already shone. Prax had the sense of walking in on a much longer conversation.
“This guy who grabs a gun first and talks later …” Naomi said. “You didn’t used to be him. You aren’t him.”
“Well, I need to be him today,” Holden said in a voice that closed the subject. The silence was uncomfortable.
“What’s wrong with the numbers?” Prax asked. Holden looked at him, confused. “You said there was something wrong with the numbers.”
“They’re saying that the death rate’s going up. But that’s got to be wrong. The fighting was … what? One day? Day and a half? Why would things be getting worse now?”
“No,” Prax said. “That’s right. It’s the cascade. It’ll get worse.”
“What’s the cascade?” Naomi asked. Amos slid the pistol into its box and hauled out a longer case. A shotgun maybe. His gaze was on Prax, waiting.
“It’s the basic obstacle of artificial ecosystems. In a normal evolutionary environment, there’s enough diversity to cushion the system when something catastrophic happens. That’s nature. Catastrophic things happen all the time. But nothing we can build has the depth. One thing goes wrong, and there’s only a few compensatory pathways that can step in. They get overstressed. Fall out of balance. When the next one fails, there are even fewer paths, and then they’re more stressed. It’s a simple complex system. That’s the technical name for it. Because it’s simple, it’s prone to cascades, and because it’s complex, you can’t predict what’s going to fail. Or how. It’s computationally impossible.”
Holden leaned against the wall, his arms folded. It was still odd, seeing him in person. He looked the same as he had on the screens, and he also didn’t.
“Ganymede Station,” Holden said, “is the most important food supply and agricultural center outside Earth and Mars. It can’t just collapse. They wouldn’t let it. People come here to have their babies, for God’s sake.”
Prax tilted his head. A day before, he wouldn’t have been able to explain this. For one thing, he wouldn’t have had the blood sugar to fuel thought. For another, he wouldn’t have had anyone to say it to. It was good to be able to think again, even if it was only so he could explain how bad things had become.
“Ganymede’s dead,” Prax said. “The tunnels will probably survive, but the environmental and social structures are already broken. Even if we could somehow get the environmental systems back in place—and really, we can’t without a lot of work—how many people are going to stay here now? How many would be going to jail? Something’s going to fill the niche, but it won’t be what was here before.”
“Because of the cascade,” Holden said.
“Yes,” Prax said. “That’s what I was trying to say before. To Amos. It’s all going to fall apart. The relief effort’s going to make the fall a little more graceful, maybe. But it’s too late. It’s too late, and since Mei’s out there, and we don’t know what’s going to break, I have to go with you.”
“Prax,” Cassandra said. No. Naomi. Maybe his brain wasn’t really up to full power even now.
“Strickland and that woman, even if they think they can keep her safe, they can’t. You see? Even if they’re not hurting her, even if they’re not, everything around them is going to fall apart. What if they run out of air? What if they don’t understand what’s happening?”