“Just take it easy for a few hours,” Dr. Brownell instructed him, severely. “If you can lie still, the process will proceed with maximum efficiency.” She was still annoyed with him for the shame that he had allegedly brought on the entire population of sleepers by virtue of his vicious attack on Riddell and Lamartine.

“How useful is the suit, really?” Matthew wanted to know. “According to Vince, the stings and fangs with which most of the local wildlife seem to be equipped go through it almost as easily as they’d go through bare skin. Even if Lityansky’s right about the unlikelihood of any biological infection, anything that gets injected that way is likely to be toxic.”

“Very few of the organisms you’ll meet on a day-to-day basis have stings or fangs,” the doctor assured him, “and they seem to be as reluctant to use them as Earthly organisms. They’re last-resort defenses, not means of aggression. Even the most poisonous ones haven’t killed anyone yet. Not that we’re complacent—we’re working flat-out to produce more effective defenses, but we’re only partway there. The main problem is the sheer profusion of likely reactions. So, no matter how good your IT is it’ll hurt like hell if you get stung by anything bigger than my thumb, and it might take as much as a week to clear all the poisonous debris out of the affected tissues.

“The suits are far from perfect, as yet—but they’re no less vital for that. If you didn’t have an artificial gut lining and air filter you’d be in deep trouble the moment you stepped down on to the surface. If he stayed inside the big bubble at Base One, drinking sterilized water and irradiated food, a man without a suit would probably get by, but you’re going to Base Three and you’ll be spending a lot of time outside. You’ll probably need all the protection the suit can provide, even if you don’t get bitten or stung.”

When she had turned away Matthew lifted his arm so that he could inspect the fabric of the suit. Once the molecular layers were properly set he would be able to reprogram the outer layer for color and certain modifications of shape, but for the time being the syntheflesh covering the hand was transparent and the “sleeve” beginning above the wrist was matt black. When he flexed his fingers he could hardly feel the extra epidermal layers, but the back of his hand looked odd because the suit had dissolved the hairs that normally grew there. He lifted his hand to touch the top of his head, and was relieved to discover that the hair growing there had been allowed to grow through. His sideburns were neatly excised at the point he had selected twenty years ago.

He opened and closed his mouth experimentally, running his tongue around his teeth. They did feel slightly strange, but he couldn’t tell whether it was the extra layer of tissue on the tongue or the extra layer on the teeth that was responsible for the difference. There was a peculiar taste in his mouth, like slightly moldy dough. His breathing seemed slightly labored, but he didn’t feel that he was in any danger of choking. He wondered whether the filters in his bronchii could keep water out of his lungs if he were ever in danger of drowning, and whether the artificial tissue could extract enough oxygen from water to let him continue breathing if he were immersed.

Although Nita Brownell had told him to lie still he decided, in the end, that stillness was exaggerating his psychosomatic symptoms, and that it would be better to put himself through the program of exercises that the doctor had designed to test and develop his inner resources. At first he stayed on the bed, but when stretching his arms and legs rhythmically back and forth began to relieve his feelings of queasiness he leapt down to the floor to practice push-ups and sit-ups.

Solari made no attempt to copy him. “I’m glad this is an Earthlike planet,” the policeman commented, as he inspected his own forearms minutely. “Imagine what we’d be wearing if it weren’t.”

“It’s because it’s Earthlike that the problems are so awkward,” Matthew told him, as he counted sit-ups. “It’s not just food allergies we have to worry about. We may not seem very appetizing to the local worms, and we’re probably not nearly as nutritious as their natural hosts, but an amino acid is an amino acid and sugars are always sweet. Just because there’ve been no recorded cases of infection or parasitism so far doesn’t mean that we’ll be safe indefinitely. Everything local that we come into contact with, deliberately or accidentally, is likely to retaliate by trying to eat us. We have all the technological advantages, but the locals are fighting on their own turf, and they have a few tricks that we’ve never encountered before.”

“You’re still worried about the insect thing, aren’t you? Not to mention the werewolves.”

“Werewolves are a red herring,” Matthew told him. “There’s a difference between serial chimeras and shapeshifting. The absence of insects may be less significant than I first thought, given the absence of flowering plants.”

“Do the plants really have glass thorns?” Solari asked. “That’s what Delgado was killed with, you know—a glass dagger. Or maybe a glass spearhead.”

“It’s not as simple as that,” Matthew told him. “But in crude terms, yes. Plants and animals alike seem to use vitrification processes to produce their strongest structural tissues. Most of the products are more like sugar crystals than window glass, but some of the upland plants that grow around the ruins have rigid tissues that can be splintered like glass to make sharp edges, and filed like glass to make sharp points. Photographs taken from above the canopy of the so-called grasslands show multitudinous globular structures like goldfish bowls that mightbe reproductive structures of some kind. I’d like to have a closer look at those.”

“I can’t make head nor tail of it myself,” Solari admitted. “I suppose I’ll have to try, though, if I’m going to spend the rest of my life down there.”

“It might be as well,” Matthew agreed.

“So tell me the difference between serial chimeras and werewolves—in terms I can understand.”

“Caterpillars become butterflies. Tadpoles become frogs. It’s a gradual progressive metamorphosis, not a matter of switching back and forth every full moon.”

“So you think the reason we didn’t see any young animals is that the animals we did see might really be different forms of the same animal?”

“Different forms,” Matthew echoed. “That might be the essence of it. On a world of chimeras, it might not make sense to think of different kindsof plants and animals—only of different forms. Everything related to everything else. Creatures that don’t just use gradual chimerical renewal as a means of achieving emortality, but as a means of achieving continual evolution.”

Solari sat up and began stroking his limbs experimentally, as if savoring the sensations of his new skin. Matthew still felt the need of distraction, so he continued his callisthenics.

“So the city-builders might not have died out,” Solari said. “They might just have changed into something else. They tried humanity and didn’t like it, so they moved on.”

“It sounds unlikely,” Matthew said, “but everything’s conceivable, given that nobody seems to have taken the trouble to find out where the limits of the chimerization processes actually lie. No—that’s unfair. I mean, nobody’s been able to figure out a way of finding out where the limits lie. If the natural metamorphoses are slow and gradual it might need more than a human lifetime just to observe them.”

As Nita Brownell had promised, Matthew felt a lot better now than he had the previous day. His body, assisted by his dutiful IT, had been working overtime to make good the deficits incurred by his organs during their suspended animation. The acceleration of his cellular-repair processes was probably going to knock a year or two off his potential lifespan, but he figured that if he could hang around until the crew obtained more information about contemporary longevity technology from Earth he would surely get some compensatory benefit from that. True emortality was apparently out of reach, but seven centuries of progress must have produced much better ways of keeping unengineered individuals healthier for longer.