Noxon could see Ram stiffen a little—he must know Noxon was talking to the mice, and so he feared that the mice might be doing something dangerous and irrevocable.
“We’re making the same alterations to this ship that our counterparts made to the backward-moving ship,” said the alpha. “So we can jump the fold without making nineteen forward copies and one backward one.”
“Are we planning to jump again?” asked Noxon.
“I believe that when the expendable finishes explaining about the civilization on the binary planet, you’ll decide that ten of these twenty ships should jump to a spot much nearer the binary.”
“Will they still skip eleven millennia back in time?” asked Noxon.
“No. Curing the replications also cures the time skip.”
“Are you ready for me to explain about the binary planet?” asked the expendable.
“I am,” said Ram. “Unless the mice now command the ship.”
“They’ve fixed it so we don’t split into nineteen pieces every time we jump,” said Noxon.
“You asked them if we’re planning to jump again,” said Ram. “Why would we do that?”
“Let’s hear the expendable and find out,” said Noxon. “The mice apparently already know what he’s going to tell us.”
The expendable took a breath before proceeding. Such theatricality from a machine that doesn’t need to breathe, thought Noxon. “Earth’s Moon was important to the evolution of life, by causing tides and controlling other cycles,” said the expendable. “But this world is really two planets, nearly equal, as close as they can be without tearing each other apart with tidal forces.”
“So both have atmospheres,” said Ram.
“Both have life?” asked Noxon.
“Both have widespread electricity and radio communications,” said the expendable. “They each monitor the other’s radio broadcasts, and I believe the ability to interfere with and eventually control remote computer systems was developed by the nearer planet in order to use it against the farther one.”
“They have a million kilometers between them,” said Ram, “and they’re attacking each other?”
“That suggests reciprocality,” said the expendable. “The nearer planet is attacking the farther one. The farther one seems to be working only to protect their own systems against attack.”
“Let me guess,” said Ram. “The one that attacked us is this aggressive one.”
“I don’t know,” said the expendable. “Whichever world emerges victorious, it will be convinced that the only way to deal with aliens is to destroy them utterly.”
“So even if it’s the nice guys on the far planet,” said Noxon, “they might still be the enemy that attacks Earth.”
The alpha mouse spoke to Noxon. “We don’t know which one is our enemy. Both must be brought under control.”
“It seems wrong to punish one world for what the other world did,” said Noxon.
“We’re not punishing anyone,” said Ram. “We’re saving the human race against a threat, and we don’t know which of these worlds poses that threat.”
“We know that both of them pose a threat,” said the alpha.
“It’s possible that both pose a threat,” said Noxon. “But to take preemptive action against both seems unfair. Stifling a civilization, a species that might be completely innocent—”
“Hold on,” said Wheaton. “Garden has already tried dozens of ways to forestall the destruction of humanity, so there are lots of timestreams in which one of these species wipes out all rivals and rules this bit of the galaxy. The other one was probably destroyed before the victor ever came near us, so we’re not the ones who snuffed them out. All we’re doing now is creating one slim timestream in which the human race survives. It is not so very much to take for ourselves, compared with what they’ve taken already.”
“So you’re arguing in favor of xenocide?” asked Ram.
“Not at all,” said Wheaton, looking horrified. “Nothing of the kind! Garden has endured for eleven millennia with tight restrictions on their ability to develop high technology, right?”
“Yes,” said Noxon.
“And that was a lid placed on the planet by other humans, right?”
“By computers,” said the expendable, “but obeying human orders.”
“So if we go into the past and put such a lid on both these species,” said Wheaton, “we’re doing to them nothing that we haven’t already done to ourselves.”
“To one portion of our species,” said Noxon. “Earth didn’t put any such lid on themselves.”
“We don’t have to destroy their whole biota in order to set up colonies here, do we?” asked Wheaton.
“It depends on what proteins they produce, and whether we can digest enough of them,” said Ram.
“I don’t suppose now would be a good era in which to make our investigations,” said Wheaton.
“You want to go into the past and see them early in their evolution,” said Noxon.
“I am what I am,” said Wheaton. “But I’m also right.”
“Put us back a few hundred thousand years ago,” said the alpha mouse, “and we’ll be their lid.”
“The mice have already suggested,” said Noxon, “that ten of our ships go to the other world, and ten stay here.”
“I wonder if versions of you are saying exactly the same thing on all nineteen of the other ships,” said Ram.
The expendable answered. “The exact wording is quite different, but yes, on every ship you have reached approximately the same point in your discussion.”
“What have the others decided?” asked Ram.
“They’re all asking their expendables what the others decided.”
“We haven’t decided anything,” said Wheaton. “But the only sensible thing is to go back in time, split the fleet in half, and explore both worlds to see what damage we might have to do in order to use them.”
“But we don’t even know what the sentient species look like on either world,” said Noxon. “How will we know which life forms in the past are going to evolve into them?”
“We have images of both species,” said the expendable. “Both worlds are regularly broadcasting visuals using primitive raster scans.” Holograms appeared in the middle of the cockpit. One species was low to the ground, with many limbs, all of them capable of grasping, and many of them with sharp claws or blades at their fingertips. The other species was tripedal, tall, and gracile, with a head crowned with vicious-looking horns. All three feet were prehensile, and one of them had two thumblike projections.
“Let me guess,” said Ram. “The low, scuttling one is the aggressive species that’s trying to take over the other side’s computers.”
“Wrong,” said the expendable.
“You wanted the roachlike one to be evil,” said Wheaton, delighted. “Easier to hate them!”
“Oh, I could easily hate them both,” said Ram. “For all we know, they teamed up to attack us. We never saw who was piloting those aircraft.”
“It’s too dangerous to go into the future to see what happens,” said the alpha mouse. “Our counterparts on the twentieth ship are still searching to make sure they’ve cleaned out all the intrusions.”
“The mice don’t want to go into the future to learn any more,” said Noxon. “If they’re scared of the aliens’ capabilities, we’d be crazy to make the attempt.”
“So we just go blindly backward,” said Ram.
“To find out if we can leave the flora and fauna on either world intact,” said Wheaton.
“We can,” said Noxon. “We can always decide not to establish colonies on either world.”
“That’s not an option,” said Ram. “We’re here to neutralize the threat. We have no way of monitoring whether we’ve succeeded without establishing a permanent, technologically powerful presence.”
“That’s not really true,” said Noxon. “For instance, we could drop off the mice a million years ago and then pop back to this time to see where we stand.”