“You think the thing in the drawing really was a pyramid?” Ike queried.

“Not a stone pyramid. Glass, maybe, or something similar. But not a tomb. Almost the reverse, in fact—but not a straightforward baby factory either. If Lynn can get enough live samples out of the mess we left behind she’ll lay the foundations for a more accurate understanding, but it doesn’t matter much that she won’t be able to feed the information through to me. I’ll have to make the most of my guesswork regardless.”

“But you’re not going to give me a preview?”

“I’m still working on the script. Trust me, Ike—if you hold the camera, I’ll improvise the show.”

Privately, Matthew wasn’t nearly as confident as he seemed, but he didn’t have any alternative. Now the stakes had been laid—and how could he possibly have refused to play or demanded a lower level of risk?—he was committed. If the world would not deliver an adequate story on cue, he would have to make one up.

Ike’s suspicions about the constancy of the environment were fully justified; it changed so little that its wonders soon became tedious. They heard other creatures, but rarely saw them. Most of the animals that lived hereabouts lived in the canopy, and those that did not fled their approach.

Matthew opened his second broadcast by reviewing the last few notes that Bernal Delgado had keyed into his notepad.

“What do they mean?” he asked, rhetorically. “ Answer downriverseems obvious enough, and we now believe that skamight mean serial- or super-killer anemone—a reference to the creatures that brought our expedition to the brink of disaster when we cleared the ground beneath the cliff in order to bring our equipment down. But what about the NVthat’s supposedly correlated with ER? If anyone has any suggestions as to what those terms might signify, I’ll be glad to hear them when I’m able to take phone calls again, but in the meantime I’m working on the assumption that they stand for nutritional versatilityand exotic reproduction. Those are two of the most stubborn mysteries we’ve had to confront as we’ve undertaken a painstaking analysis of the ecosphere of the world that some of you call Ararat and others Tyre.

“Nutritional versatility may seem at first glance to be a non-problem. So organisms whose activity and tendency to eat everything in sight entitles them to be thought of as animals also have the purple chloroplast-equivalents that allow them to fix solar energy, just as plants do—why shouldn’t they? Isn’t the situation on Earth the surprising one? Why should there be such a clear distinction between Earthly plants and animals when every species might, potentially, enjoy the best of both worlds? Why is nutritional versatility the Earthly province of a few exotic plants like the Venus flytrap?”

Matthew paused, looking beyond the camera at the man holding it. Ike had been concentrating on the problem of keeping the camera steady, and didn’t immediately register the slight change of attitude. When he did, he took his eye away from ther viewfinder momentarily to acknowledge the contact. He couldn’t shrug his shoulders without shaking the image, so he contrived a gesture of reassurance with a forced smile.

Having cleared his throat Matthew went on.

“Well, the logical answer is that once an organism can obtain energy by eating, the extra margin of assistance to be gained from continuing to fix solar energy is too small to be worth keeping, so there’s no selective pressure to retain it. The number of animal species is, of course, limited by the fact that they all have to have something to eat, so there have to be lots of plants around in order to support any animal life at all, but the more animal life there is the more scope is opened up for animals that eat other animals. Plants can only dabble in eating animals if there are enormous numbers of plants around that don’t, and they find it difficult to compete with animals because they’re sedentary. If you’re an eater, it’s a great advantage to be able to get around—waiting for your food to come to you is obviously a second-best strategy—and an organism needs so much energy to get around that if it’s going to do that, it might as well be a specialist eater.

“So how come this world is so rich in organisms that have kept their ability to fix solar energy in spite of the fact that they can eat and get around? The purple worms don’t even seem to make strenuous efforts to get out into the sun when they can. They lurk in the shadows like any other stealthy predator. How can that make sense?

“Well, I can only see one way in which it mightmake sense. If the super-slugs keep chloroplast-analogues they don’t bother to use on a day-to-day basis, there must be times when they doneed to use them. Rare times, maybe, but vitaltimes—times when that energy-fixing capability is so vital that it’s carefully sustained through all the times when it’s not. And that’s where the exotic reproduction has to come in.”

He looked away as a sudden movement caught his eye, but it was only something falling from the canopy. He looked back before Ike moved the camera.

“The most important difference between life on Earth and life on Ararat, alias Tyre, is that sex isn’t the only way of shuffling the genetic deck so as to produce the variations on which natural selection works. Here, sex involves cells within a chimerical corpus rather than whole organisms. You could say that all the local organisms are actually small-scale colonies of continually cross-breeding individuals. And they’re probably all emortal. That doesn’t matter much to the simplest ones, because they never live long enough to die of old age; they always get eaten long before they reach the limits of their natural life spans. The more complicated ones are a different matter.”

Matthew hesitated again, but this time it was purely for dramatic effect. Ike understood that, and stayed focused.

“Earth’s ecosphere was shaped by what Bernal Delgado used to call the sex-death equation. The essence of life is reproduction, but there are two kinds of reproduction. There’s the kind by which organisms make new organisms and the kind by which organisms reproduce themselves. The cells of your body are continually replaced, so that every eight years or so there’s an entirely new you, almost as good as the old one but not quite. We humans—and I mean wein a narrow sense, because there’s a new human race on Earth now that doesn’t have this particular disadvantage—deteriorate like a chain of old-style photocopies, each image becoming a little more blurred than the last. Eventually, we die of growing old, if we haven’t already been killed by injury or disease. In the meantime, though, most of us make a few new individuals, by means of sexual reproduction. We die, but the species goes on—and we owe our existence to the fact that natural selection used to work on the new individuals our remoter ancestors made, weeding out the less effective ones. We owe our intelligence to the slow work of natural selection, which perfected the union of clever hands, keen eyes, and big brains that pushed our forefathers ahead of all their primate cousins.

“To us, that all seems perfectly natural, and so it is—but it needn’t have been that way. Here, evolution took a slightly different path. Here, sex is routinely confined to the kind of reproduction by which the local equivalents of organisms reproduce themselves. I say the local equivalents of organismsbecause they’re not the same as Earthly organisms in the sense of being genetic individuals. They’re compounds: chimeras. That seems odd, because they don’t look like the chimeras of the Earthly imagination: they’re not compounds of radically different species, like griffins, and they don’t seem to go in for dramatic metamorphoses—at least, not on a day-to-day basis. But they doreproduce in the other sense, because they have to, and they aresubject to the kind of natural selection that drives an evolutionary process, because they have to be. We can see that, just by looking around, because we can see perfectly well that this ecosphere is as complex as Earth’s, and that the logic of convergent evolution has produced all kinds of parallel bioforms. It may seem puzzling at first that we can’t see the second kind of reproduction going on, because no alien visitor to Earth could possibly miss it if he hung around for a year or two, but when you think about it carefully, you can see that it’s much less puzzling than it seems.”