“Seven hundred years of progress,” Matthew said, keeping his own voice low even though he knew as well as well as Solari did how futile the gesture was, “and even Hopeis home to armed men. For all we know, there’s a full-scale civil war in progress. If Shen Chin Che were dead, he’d be spinning in his grave. If he’s not …”

He wanted to follow that train of thought further, but Solari was keeping a tighter focus on the matter in hand. “Whoever killed Delgado on the surface may have friends up here,” the policeman observed. “Mr. Riddell might be there to protect us.” He didn’t sound as if he believed it.

“We were all supposed to be on the same side,” Matthew went on, angling the trajectory of his conversation very slightly to take aboard Solari’s comment. “Crew and human cargo, scientists and colonists, all working together in the same great scheme. The whole point of building the Ark was to leave behind the divisions and the stresses that were standing in the way of saving Earth. We were all supposed to be united in a common cause, having put the past behind us. How could that go badly wrong in three short years?”

“And seven hundred long ones,” Solari reminded him.

“Are we being too paranoid, do you think?” Matthew asked.

Solari didn’t have time to answer that one before Frans Leitz came back in. “The captain will see you both at eight-zero,” the boy said. “He apologizes for not having been there to greet you when Dr. Brownell brought you out of the induced coma for the last time, but he’s very busy.”

Matthew realized that he had no idea what the present time was, and couldn’t be sure what eight-zero might signify. There was no clock on the wall of the room, and he remembered now that Nita Brownell had said something odd about fifty hours being the equivalent of five days of “old time.”

When he asked for an explanation, Leitz explained to him that the ship operated on metric time, using an Earth-day as a base because it suited the Circadian rhythms built into crew physiology. Each day was divided up into ten hours of a hundred minutes, which were further subdivided into a hundred seconds. Surface time had kept the same basic structure, but had adopted the local day as a base, thus resulting in a desynchronization of ship and surface time. The local day, determined by the planet’s rotation, was 0.89 of a ship day.

“We think that’s another of the reasons for the groundlings’ continuing unease,” Leitz told them. “It’s proved to be surprisingly difficult to modify the physiology of Circadian rhythms, but we’re sure that they’ll solve the problem soon. If only they could be patient … anyhow, the planet’s year is one point twenty-eight Earth-standard, but its axial tilt is very slight, so its temperate-zone seasons aren’t nearly as extreme. That’s not problematic, although Professor Lityansky thinks it has something to do with the strange pattern of local evolution. He’ll explain it when he briefs you tomorrow, Professor Fleury. That’s at three-zero, provided that you’re up to it. How do you feel now?”

“Better,” Matthew assured him, drily. “Professor Lityansky’s busy too, I dare say.”

“Extremely busy,” the boy replied. “He’s working flat-out trying to figure out exactly what we need to do to make the colony work. He’s under a great deal of pressure, because the groundlings hold him primarily responsible for the decision that the world is sufficiently Earthlike to qualify as a clone. The decision to go ahead with the colonization wasn’t entirely his, of course, but his genomic analyses provided the relevant data and his judgment of their significance was crucial. He feels badly let down by some of the people on the surface.”

“How come their judgment is so different?” Matthew asked.

Leitz hesitated, but eventually decided to answer the question. He was becoming more relaxed now, and a certain boyish enthusiasm was beginning to show through. “Our data was limited, of course,” the youth conceded. “Our nanotech is way behind Earth’s, and we haven’t been able to improve our probes to anything like the same degree while we’ve been in transit. Apart from evidence gathered at long-range by our instruments, we had a very limited range of surface-gathered samples to work from. They were adequate for genomic analysis, but most of what we had on which to base our decision was fundamental biochemical data. The photographs taken by our flying eyes showed us what the local plant life looked like, but we didn’t have any real notion of the ecology of the world, or even of its diversity, let alone its evolutionary history. Once the first landing was complete, the biologists on the ground began to fill in the other parts of the picture—and they began to get alarmed.

“Some of the groundlings began to argue that Professor Lityansky had made a bad mistake, because he hadn’t been able to think through the consequences of his genomic analyses. The extreme view is that the colonization should have been put on hold as soon as it was realized that the local ecosphere wasn’t DNA-based—but that’s absurd, isn’t it, Professor Fleury?”

Matthew could see what the young man was getting at. When Hopehad set out from the solar system its scientists had not the slightest idea exactly how alien any alien life they discovered might turn out to be. Having only had a single ecosphere on which to base their expectations, they had no way to arbitrate between hypotheses that held that life throughout the universe was likely to be DNA-based, or that DNA would turn out to be a strictly local phenomenon unrepeated anywhere else.

Matthew had always had more sympathy for the former opinion, not because he lent any credence to the panspermist myth—which held that life had originated elsewhere and arrived on Earth while being dispersed throughout the expanding cosmos—but because it seemed to him that natural selection operating in the struggle for existence in the primordial sludge would probably have found the same optimum solution to the business of genetic coding that would materialize elsewhere. In the absence of any comparative cases, however, the matter had been pure guesswork—until Frans Leitz’s forbears had found the “sludgeworld” whose bacteria employed a different molecule.

Armed with that foreknowledge, Lityansky and his fellows would have been less surprised than their newly defrosted colleagues to find that the new world’s ecosphere also had a different coding-molecule. Indeed, Professor Lityansky might well have taken that as good evidence that DNA wasa purely local phenomenon, unlikely to be repeated anywhere in the universe—given which, any would-be colonists of new worlds would simply have to take it as given that they could not expect to find conditions entirely to their liking.

“I wouldn’t call it absurd,” was what Matthew was prepared to say to Leitz at this stage. “People had argued about what might or might not qualify as an Earth-clone world long before Hopewas a gleam in Shen Chin Che’s eye. It wouldn’t have been regarded as an extreme view to say that an ecosphere had to be DNA-based to qualify as a clone. On the other hand, we didn’t set out with the proviso that we had to find DNA in order to found a colony. We set out with the intention of making the best of whatever we could find.”

“Exactly,” said Leitz. “And that’s what we have to do. The fact that Earth came through its own ecocatastrophe doesn’t make any difference to our quest; there was never any question of going back. And the fact that the other probes sent out in this general direction haven’t located any other world that’s even remotely Earth-like means that we simply can’tpass up this chance. Isn’t that so?”

“I can’t answer that until I have more facts at my disposal,” Matthew said, “But aren’t you avoiding the most important issue of all? If this world is inhabited …”