“When you say ‘no doubt’ it means that there is reason to doubt,” said Ram Odin. “People only say ‘no doubt’ when they know they’re making a judgment based on insufficient information.”

“They don’t have facemasks,” said Rigg Noxon. “They can’t hear the mice or talk to them. They can’t ask.”

“You can hear them,” said Ram Odin. “You can ask.”

“We don’t necessarily believe the mice,” said Rigg-the-killer. “They already killed Param once. Our goal is to save the human race on Garden, not provide mousekind with a depopulated Earth for them to inherit.”

“There are too many players in this game,” said Ram Odin.

“The mice were planning to take several billion of them out of the game entirely,” said Rigg-the-killer.

“Not all the players are equal,” said Ram Odin. “Make a decision and make it stick.”

“You’ve been alone with the expendables far too long,” said Rigg Noxon. “You think because you can play God with other people’s lives, you have a right to do it.”

“You think,” added Rigg-the-killer, “that because you’ve been doing it for so long, you’re fit to do it.”

“Power is power,” said Ram Odin. “If you have it, then it’s yours to use.”

“The sheer stupidity of that statement,” said Rigg-the-killer, “makes me wonder how Garden struggled along for eleven thousand years with you in control.”

“A child lectures an eleven-thousand-year-old man,” said Ram Odin.

“There are thousands of examples in history,” said Rigg-the-killer, “of people with power who used it in ways that ended up destroying their power and, usually, a whole lot of innocent ­people, too.”

Rigg Noxon listened to his other self and realized: Having killed Ram Odin changed him. Rigg Noxon would not have treated Ram that way—as if his statements were worthless. Rigg Noxon would have tried to take them into account. Rigg Noxon would have spoken as youth to adult. But Rigg-the-killer must still be full of anger toward Ram Odin, who had, after all, tried to kill Rigg first.

We lived exactly the same life until a few minutes ago, for me; a few weeks or months ago, for Rigg-the-killer. But we are different people.

“So you leave the decision up to Umbo and Param,” said Ram Odin.

“And Olivenko and Loaf,” said Rigg Noxon. “We’re companions, not a military force with someone giving orders and everyone else required to obey.”

“Besides,” said Rigg-the-killer, “I don’t want to leave the future of the human race on both planets in the tiny little hands of the sentient mice of Odinfold.”

“What do you plan, then?” said Ram Odin. “To sneak on board the Visitors’ ship?”

“Yes,” said Rigg-the-killer.

“No,” said Rigg Noxon, at exactly the same moment.

They looked at each other in consternation.

“We could sneak on,” said Rigg-the-killer. “We can slice time the way Param does, now that we have the facemask to let us perceive units of time that small. We’ll be invisible for the whole voyage back.”

“And when we get there, what will we do?” asked Rigg Noxon. “There is only a year between the coming of the Visitors and the return of the Destroyers. Most of that must have been spent voyaging. So when they return to Earth, the response, the decision, it’s immediate. What are we going to do, give speeches? Hold meetings?”

“Your talents with time don’t make you particularly persuasive,” said Ram Odin. “And powerful people don’t change their minds because of speeches.”

“As soon as we arrive,” said Rigg-the-killer, “we jump back in time and learn everything we need to know, make the connections we need to make.”

“Of course,” said Rigg Noxon. “We’ll fit right in. Nobody will notice we’re from another planet. I’m sure that in all human cultures, kids our age will be taken seriously and be able to influence world events. Especially kids wearing parasites on their faces.”

“Or you could figure out who needs to be assassinated and kill them,” said Ram Odin.

Both Riggs looked at him in consternation. “We know you’re an assassin,” said Rigg-the-killer. “We’re not.”

“On the contrary,” said Ram Odin. “You came here bragging that you are.”

“In self-defense,” said Rigg-the-killer. “But you—when your ship made the jump and you realized that there were nineteen copies of the ship, of you, of all the colonists, you made the immediate decision to kill all the other versions of yourself.”

“Precisely to avoid the kind of weak-minded, incoherent ‘leadership’ you exhibit,” said Ram Odin. “And please remember, I’m the Ram Odin who didn’t order the death of anybody.”

“No, you’re the sneaky one who hid out until the quickest killer version of yourself had died of old age and then you established your colony in Odinfold, violating most of the decisions your murderous self made and then living forever,” said Rigg-the-killer. “Proving that you don’t always think one person is fit to make all the decisions for everyone—even when that person is a version of yourself.”

Ram Odin rolled his eyes and then nodded. “It’s extremely annoying hearing this from a child.”

“But no less true,” said Rigg-the-killer.

“Once you’ve killed somebody,” said Rigg Noxon, “can anybody honestly consider you a child anymore?”

“Then you’re still a child because I stopped you from killing anybody? And I’m an adult?” asked Rigg-the-killer.

“Yes,” said Rigg Noxon. “In a way. Maybe because I’m a child, or maybe because of the quirks of causality arising from the different paths we’ve walked recently, I have a slightly different plan.”

“Either we go back with the Visitors or we don’t,” said Rigg-the-killer. “The difference isn’t slight.”

“Don’t be like him,” said Rigg Noxon, “and assume that because you didn’t think of it, it must be wrong.”

“Think of what?” asked Ram Odin impatiently.

“I think I should go to Earth, but not with the Visitors,” said Rigg Noxon.

A couple of beats of silence, and then Ram Odin shook his head. “This ship can’t fly again. The inertial field kept it from damage when it collided with Garden, but we can’t raise it from the planet’s surface. Even if we could get rid of the millions of tons of rock above us right now, the ship doesn’t have enough power to lift us out of the gravity well of Garden.”

Rigg Noxon shook his head. “You’re forgetting what we do,” he said.

“He means for one of us to go backward in time to when the ship arrived,” said Rigg-the-killer. “He means for us to keep making little jumps into the past, following your path moment by moment, backward along with this ship as it slammed into Garden. I mean, as it unslams, backing out of this hole and up into space, backward and backward until it gets to Earth. Until we get to the point where you launched on this voyage.”

“This ship was built in space,” said Ram Odin. “It never was on Earth.”

“We go back to when it was built,” said Rigg Noxon. “Then we follow someone else’s path off the ship.”

“If you can even do that,” said Ram Odin, “what’s the point? Why not go back with the Visitors as the other Rigg suggested and then jump back in time?”

“There are some key differences,” said Rigg Noxon. “First, we don’t have to spend the voyage in hiding—not the way we would by slicing time on the Visitors’ ship.”

Rigg-the-killer was nodding. “And we’ll have the jewels,” he said, holding up the bag of jewels that gave them the ability to control the ships’ computers—and stored all the information the computers had gathered in the meantime.

Ram Odin looked at the jewels. “Each time you jump backward,” said Ram Odin, “the ships’ computers and the expendables will be sensing these things for the first time.”

“And each time,” said Rigg Noxon, “it will give them a complete account of everything that’s been learned in the eleven millennia of history on Garden.”