“Or we can wipe out all the native life and make a new Earth,” said the alpha mouse.

“Whether or not we have nineteen or twenty ships,” said Noxon, “we can create as many wallfield generators as we want, and the expendables to tend them, right?”

“Yes,” said the alpha mouse.

“Yes,” said Ram Odin. “Very interesting. Wallfolds no matter what.”

“So the deal I offer is this. All the wallfolds have the same technology cap as on Garden. Every wallfold has an expendable or two. But we create enough wallfolds that besides having enough for several—or twenty—human colonies, we also have one or two wallfolds which have only mice as their sentient occupants.”

“How generous,” said the alpha mouse.

“Irony is still a lie,” said Noxon. “Hear me out. We also have a couple of human colonies that are shared with mice. Joint colonies. To see what happens. To see if we and you can grow and develop together, cooperatively or at least without slaughtering each other.”

“Unlikely,” said the alpha mouse.

“Why not?” said Ram Odin.

“I think it’s very likely,” said Noxon. “Especially because the ship’s computers will be programmed to wipe out any wallfold where either the humans or the mice find a way to exterminate the other species.”

“Maybe we can interbreed,” said the alpha mouse.

“I hope not,” said Noxon. “And we also have two or three wallfolds where the aliens are allowed to continue their evolutionary development—but with the same technology cap. At least one of those will also have mice.”

“The aliens should all have mice,” said the alpha mouse.

“They will have expendables. If possible, expendables redesigned to look like them. If not, then the same ones we have. They’ll all be supervised.”

“And that’s the plan?” said the alpha mouse. “You thought of this all by yourself?”

“It’s the obvious way to proceed,” said Noxon. “Everybody gets a home.”

“A reservation,” said the alpha mouse.

“A place to develop independent of the others.”

“But with a cap on what we can achieve,” said the alpha mouse.

“Not really,” said Noxon. “Because you’ll still have the ability you have right now—to move objects and manipulate things as tiny as genes, in both space and time.”

“They can do that?” asked Deborah.

“They’re very talented,” said Ram Odin.

“So everybody is completely at their mercy,” said Wheaton.

“That’s why we’re making this deal now, while there are still only twenty of them,” said Noxon.

“But they’ll lie,” said Ram Odin.

“I think they won’t,” said Noxon. “Because they can see that this is the best long-term protection for their descendants as well as ours.”

“Why?” said Ram. “How? We can’t develop our tech past a certain point, while theirs is invisible and already far beyond anything we can do.”

“Because every human colony will start with a Ram Odin and a Noxon,” said Noxon. “And that means that we’ll have the power to go back in time and undo whatever the mice do wrong. Or even undo the original placement of the mice into the ­colonies. Because part of the deal is this: The mice go into stasis during the colony founding, and they don’t get colonies of their own until at least three hundred years. And the release of the mice into each wallfold they’re allowed to enter will take place in public, and under circumstances that will make it easy for future human timeshapers to come back and prevent it.”

“That’s not foolproof,” said Wheaton. “I can think of—”

“So can the mice,” said Noxon. “But whatever they think of, we can probably think of a way to get around them and undo it. If we choose to spend our futures in stupid competition with each other. But maybe we won’t. Maybe the mice will see that keeping promises works out better for them than going to war with timeshaping humans.”

“I see it already,” said the alpha mouse. “And so will all my descendants.”

“Come on,” said Noxon. “The reason your testes aren’t visible is because you’ve been castrated. You won’t have any descendants.”

“Not me personally,” said the alpha mouse. “I think of all the babies in their uteruses to be my children, so to speak.”

“Well, Father of Great Nations, answer me: Will you accept this plan and abide by whatever decision I make when we reach the alien world?”

“I accept the plan and I promise to abide by your decision,” said the alpha mouse.

“How is that different from what you would say if you were already determined to break every promise and take over the world and the ship and everything?” asked Noxon.

“It isn’t different,” said the alpha mouse. “But I mean it. And you’ll see that I mean it because I will no longer seize every opportunity to subvert you.”

“So our alliance is set?” asked Noxon.

“We have only one condition,” said the alpha mouse.

“Which is?” asked Noxon.

“You take at least one of us into the future with you and let her connect with your computer system when the aliens take it over. So we can make some assessment of what they’re capable of.”

“No,” said Noxon.

“Seriously? Why not? Knowledge is essential.”

“Knowledge is power,” said Noxon. “You’ve been trying for thousands of generations to break into the programming of the ships that control Garden, in order to reprogram them to allow you through the Wall and to let you develop higher tech than they currently permit. And you’ve failed. But these aliens broke into our computer systems, took them over, and used them to destroy us. You want to see how it’s done.”

Silence for a few moments. Then: “That was truly not my plan,” said the alpha mouse. “If it had been my plan, then that means I was already acting in bad faith and our alliance was already shattered. But I was acting in good faith. I really need to understand what their capabilities are. We will be much safer approaching their planet if I have some idea of how to resist them and keep them from taking over our ship remotely.”

Noxon thought for a while. Finally he spoke to Ram Odin. “I think I’m going to take one of them forward in time to watch the alien invasion while hooked into the communications network.”

“I thought your argument against that was excellent,” said Ram Odin. “Flawless, in fact.”

“It was,” said Noxon.

“So what did they say to change your mind?” asked Ram.

“More promises,” said Noxon, “which are exactly what they’d say if they’re telling the truth or if they’re lying.”

“So you have no idea,” said Ram Odin.

“You have to leap sometimes,” said Noxon. “You have to trust.”

“And if you’re wrong to trust them?” asked Ram.

“It’s in their self-interest to keep the alliance at least until we get to the alien world,” said Noxon. “At least until we’ve eliminated that threat. After that—well, we’ll see.”

“That’s it? We’ll see?”

“All alliances between rivals take that form,” said Noxon. “We work together as long as it makes sense to do so—and then see how the other side behaves when some of the incentives for cooperation are removed.”

“Very wise,” said Wheaton.

“It’s time to get these mice out of here,” said Noxon. “Come on, all of you climb up on me. The mice,” he added quickly. “Talking only to the mice.”

They scampered up into his clothing. The facemask remained aware of every one of them. “You won’t regret this,” said the alpha mouse.

“Good,” said Noxon, already regretting it, yet sure there was no better way. “Now the rest of you, kindly take my hands. We’re jumping back into the future one last time. I believe we have a car parked nearby waiting to take us back to civilization.”

The decision about the mice had been entirely Noxon’s to make. But since Deborah and Anthropologist Wheaton were not crucial now to any course of action, he could leave their future up to them.