"Doesn’t the handoff cause a lot of earthquakes?" asked Dale.

"The Tosok home world has no moon," said Hask. "It probably did once, or else our world would have an even greater greenhouse effect than it does now; Clete told me that without the moon, Earth’s atmosphere would resemble Venus’s — a thick blanket covering the world. Our old moon’s gravity doubtless skimmed off some of our original atmosphere, but that moon must have been lost during one of the handoffs. Anyway, without your own moon churning up Earth’s interior through its tidal effects, you would not have any plate tectonics; Earth is, after all, unique among the planets in your solar system in having such things. Without crustal plates, you do not get earthquakes; they are unknown on our world. Except for the impact on our climate, the handoffs proceed quite smoothly."

"But if handoffs occur only every four hundred thousand years," said Frank, "your race can’t have known one yet. I mean, you guys are advanced beyond us, but by hundreds of years, not by hundreds of centuries."

"True," said Hask. He paused. "Our fossil record is scantier in many ways than is yours. But since we have no plate tectonics, no portion of our crust is ever subducted and destroyed through the passage of time; although there are fewer fossils, our record is contiguous in a way that yours is not.

We were astounded when our geologists found proof in core samples of the huge periodic temperature changes our world had undergone for at least many tens of millions of your years. But although the fossil record shows that a few species die out at each great freezing, most simply continue on immediately after the thaw. Life on our world has evolved to deal with the handoffs — or, more precisely, only those lifeforms that had an ability to survive freezing survived the first handoff, and all current lifeforms are descended from them." He paused. "Perhaps it is not coincidental that our hearts are primitive compared to yours; I understand many earthly fish and amphibians — creatures with similar hearts — can also survive periods of freezing."

"That’s why there was no hibernation equipment aboard your ship," said Dale.

"Exactly. Simple cold temperatures are enough to induce hibernation. The two centuries of sleep required for the journey from our planet to here were insignificant; we could as easily have gone many hundreds of thousands of years."

"All of that is fine," said Frank, "but then what did you mean when you said your starflight was about survival?"

Hask’s tuft danced in agitation. It was a moment before he replied. "Our race sent starships to all the worlds neighboring ours to see if there was any life there. Actually, although Sol is our closest neighbor, we dispatched much faster ships to several more-distant stars, including the ones you call Epsilon Indi and Epsilon Eridani, from whom we had already detected radio signals. As you may have noticed, we make much less use of metal than you do; again, the lack of lunar churning has kept most of our world’s metals deep beneath the crust. We simply did not have the resources to send equally sophisticated ships to all possible destinations. When we left Alpha Centauri, two hundred of your years ago, you had not yet begun to broadcast by radio, of course, and so you were not a high-priority target.

"Still, we were not just looking for intelligent life, you understand, but also for potentially intelligent life. Four hundred thousand years ago, after all, your own species did not exist — but its forebears did. These missions were sent to ascertain if any intelligent life was present now on neighboring worlds, or if any might arise by the time the next long sleep was over. For eons, life on our world has passed peacefully through the periodic sleeps — after all, the entire ecosystem shuts down during them, so we have no fear of indigenous predators. But what about predators from the stars?

What about hostile worlds bent on conquest? No aliens had yet visited our world, so we assumed we were the most advanced form of life in the local universe. But if we were to stop evolving for four hundred thousand years, who knows what now primitive lifeforms from other worlds would — what was the word you used, Frank? — would leapfrog past us during that time? Who knows what threat they might pose to us when we reawaken? Who knows if they would even allow us to reawaken, or would kill us all while we slept?"

"God," said Dale. "You came here to wipe out all the life on Earth."

"Not all the life, Dale — I doubt we could do that, anyway. But we certainly intended to wipe out all the vertebrates, just to be on the safe side."

Frank felt his jaw go slack. All the vertebrates. Jesus Christ. It was so big, so massive — and then, all of a sudden, it had a human face. Maria. They would kill her, along with everything else. "That’s — that’s monstrous," said Frank, his voice quaking with rage. "That’s downright evil. What gives you the right to go around the galaxy, wiping out whole planets?"

"A very good question," said Hask. He looked at Seltar, then continued.

"We used to think we were the divinely created children of God — and that, of course, would be sufficient to give us the right to do whatever we deemed necessary; if God did not want us to do it, after all, she would thwart our attempt. But when we discovered that that is not true, that we are merely products of evolution, well, then, the question of having the right to do something no longer enters into it. Survival of the fittest, no?

The struggle for life, no? Competition, no? If we can advantage our species, then we have the right and the obligation to do so."

"Jesus," said Dale.

"I agree," said Hask.

"Pardon?"

"Do I misunderstand you? When you invoke the name of your putative savior in that tone of voice, you are expressing disgust, no?"

"Well — yes."

"Then we do agree. I share your disgust, and so does Seltar. But we are a tiny minority. Our hope was that once the others met you, they would realize that it would be inappropriate to wipe your planet clean of life. But they have not wavered in their plan. Indeed, if it had not been for the accident in your Kuiper belt, they would have already completed that task: our mothership is equipped with a high-powered wide-angle particle-beam weapon, which we would have trained on your world from orbit. In short order, we would have irradiated the entire surface of your planet. Indeed, the other Tosoks still intend to do that, once the repairs are complete."

Dale’s deep voice: "Do the other Tosoks know that you’re a… a…"

"A traitor?" Hask lifted his front and back shoulders, an acquired human gesture. "Do not hesitate to say it; I am comfortable with the term. No, they do not. We had two possible hopes. The first was to prove that your race was divinely created — if we could show that you were the true children of God, our people would never have harmed you. But your form is as imperfect as ours."

"And the other hope?"

"Seltar. If the mothership was repaired, and the attack on Earth imminent, then Seltar would sabotage the ship — something she could only do if no one suspected her existence. The eight of us would have been marooned here, but that would be — what is your metaphor? — a small price to pay."

"If you woke up first, why not just disable the ship then?" asked Dale.

"I do wish to return home, counselor."

"You could have killed the other Tosoks in their sleep," said Frank.

"God did not move me to do that; despite what happened to Clete, I am no murderer."

Frank’s voice was hard. "And what, precisely, did happen to Clete?"

"He discovered that Seltar was still alive. I had been careless. While the others were off at the lecture by that paleontologist, I took the opportunity to contact Seltar by radio; I missed her so much, I could not bear not to speak with her. Although my translator was off, Clete overheard me — I had not realized that he, too, had demurred from attending the lecture to work on his script, and he had the habit of pacing the halls as he thought of what he wanted to write. Clete realized that I was speaking to a Tosok other than the ones at the lecture — and doing so in realtime. I chased him back to his quarters and tried to explain to him the necessity of keeping the secret. He said he would not tell anyone — but I could tell he was lying; his face had grown brighter."