The binaural sensors were active, too, reporting soft clicks from the rover’s articulated limbs along with the crackle of branches and the rustle of dry leaves. Nick was becoming used to those sounds when they were interrupted by a coughing grunt, right in front of the rover.

“What’s that?”

“Homing in. We’re getting close to the targets.” Gordy Rolfe was perched on the edge of his seat. “Here we go.”

The rover had tracked around a stand of broad-leaved bushes. It halted, showing a view of a small clearing bordered by towering ferns. Three creatures tore at a bloodied corpse on the ground.

Nick took one look at the gray scaly heads with their sword teeth, at the thick tails and the massive hind legs, “Gordy, you’re crazy! If they broke through here . . .”

Rolfe cackled. “Not a problem! Try again, Nick. See the plants around them — and see what the three are eating.”

Nick looked again. The eyes were large, but black and expressionless as a fish’s eye. The hide was gray and thick, scaly except for a softer patch on the front of the neck where the skin formed a pouch like a heavy dewlap. The color there heightened to a warm beige. The forelimbs, in contrast to the heavy hind limbs, appeared weak and useless and too short to grasp or hold a prey. The animals, squatting back on their haunches, were clearly and comfortably bipedal, certainly meat-eaters, and definitely dinosaurs.

The shock of recognition was so great that Nick had been oblivious to everything else. Now he could recognize the scale of what he saw. The dead animal they were eating was a fat rabbit, fully half as big as the beasts around it. And as Rolfe said, the plants were the key to sizing other objects. The ferns in the background loomed over the rover, but the rover rolfes were only a couple of feet high, designed to wriggle their way easily through the jungle.

The minidinosaurs gave the new arrival one quick inspection, growled, and went back to their feeding.

“T. rex stock, of course,” Gordy said. “But I mixed in a fair amount of DNA from their own ancestors. You know, the early dinosaurs and most of the late ones weren’t particularly big. The ones we’re looking at are less than three feet tall.”

“You don’t build — full-sized ones. Do you?”

“Not anymore. Of course, I did it years ago. Everybody wants to do a T. rex for starters. I mean, it’s so famous you more or less have to try.”

“You failed?”

“Oh, no. The genoforming was no problem — it’s actually more difficult to create dwarf variations, like these, because you have to change the proportions from the original.”

Nick examined the animals in the holographic display more closely. The midget dinosaurs had massive hind limbs and a thick tail, slightly out of proportion to their size. They also moved a little clumsily — but each of those needle teeth was close to an inch long.

“They look pretty dangerous to me.”

“No more so than a dog of the same size, and not nearly as intelligent. Each one of these weighs about thirty-five pounds, though there are a few larger sizes in the habitat — up to a hundred pounds. Mind you, I’m not saying they aren’t dangerous at all. Even with these minisaurs, you wouldn’t want to go alone into the habitat without a weapon. They’re not pack animals, and they don’t hunt in groups, but they’ll gang up to make a kill. Two or three might easily bring down a human.”

“What do they eat?” The rabbit had been dismembered and little of it remained.

“Ah, now that’s a curious fact. They’ll eat most things if they have to, amphibians and reptiles and other dinosaurs. But given a choice, they seem to prefer mammals. It makes you wonder if that reflects some ancient struggle. You know, we usually think of the mammals as coming after the dinosaurs had died off, but there were mammals — small ones — long before that. One old theory was that early mammals did in the dinosaurs, by eating their eggs. And maybe a preference for mammalian meat is an evolutionary survival mechanism for the dinosaurs.”

“Would a dinosaur eat a human?”

“I don’t know, but I don’t see why not. We’d make a good meal for a pack of minisaurs. Of course, for a full-sized allosaur or tyrannosaur a human wouldn’t be more than an appetizer. Do you realize how much it takes to feed a full-grown T. rex? Or a big herbivore, like a titanosaur? I tried it. This whole habitat can support only a handful of large plant-eaters — and they crap like you wouldn’t believe. The tyrannosaurs were even worse; I had to keep importing meat from outside. That screws up the whole idea of a self-supporting habitat. It just wasn’t worth it, and I went to the miniature forms. I found that I can do the experiments I’m interested in just as well with them.”

“Which are?” Nick could imagine some pretty unpleasant possibilities, none of which seemed beyond Gordy’s limits.

“Answering what-if questions. Nature was unkind to the dinosaurs. They existed in the same era as the mammals, but I don’t think the two forms ever had a real head-to-head competition. All the mammals were small when the asteroid hit Chicxulub and the dinosaurs became extinct. Flying reptiles went away at the same time, but I’ve not done any work with them yet. What I have done, though, is absolutely fascinating. It’s getting too dark to track in the habitat with visible light. Later we’ll watch the nocturnal forms, but meanwhile let me show you some of my results.”

Rolfe stood up and did something invisible at the console, then moved back to stand directly in front of the ten-foot holograph. The natural light had faded to a deeper gloom, and Gordy Rolfe became a small, dark figure, hopping about against the background of the three-dimensional display. When he spoke again, his voice matched the animation of his manner.

“Fourteen years ago I set up my first full-scale simulation. The habitat was self-contained and isolated except for the water supply and simulated solar radiation. I put in a mixture of plants from today and those found in this region a hundred million years ago — see, I didn’t want to tilt the odds one way or the other. I put in floor and ceiling sensors that can identify, track, and inventory every animal species, so there would be a continuous census of habitat contents. And I seeded the habitat like this.”

A big group of animals stood frozen in holographic relief. Nick recognized four large meat-eating dinosaurs, which he thought from their size were Allosaurus. They, together with four lumbering specimens of Diplodocus, dwarfed everything else in the holo frame.

Gordy moved around on the edge of the holograph. “This is shown at one-quarter scale, but everything I put into the habitat was full-sized. See, here are the big modern predators — I chose tigers, because they function better than lions in a jungle environment. I didn’t want to use zoo specimens, they might be bred for docility, so I went to the Indian genome bank for original DNA templates. And here are hypsilophodons — small, fast herbivores, according to the books, but these seem more like omnivores, they’ll eat anything. And here’s a bunch of little saurischian plant-eaters, and these are wolves — no, I’m wrong, they’re hyenas — and if you look at the bottom, we have the smallest forms, shrews and mice and some of the saurornithoids that are not much bigger.”

Nick was listening, but with only half his attention. While Gordy Rolfe spoke with such enthusiasm about his simulation, the rover rolfe was still out in the real habitat. So were the meat-eating minisaurs. It was too dark to see anything, but the rover’s audio system was working. Unpleasant crunching sounds were interrupted by grunts and snorts and once by a startled, high-pitched squeal.

“Release them into the habitat all at once,” Rolfe went on. He waved his short arms. With a little imagination, the stooped, big-headed form silhouetted against the display could itself be one of the dwarf meat-eaters. “Provide water and light in realistic weather patterns, stay away, and see what happens. I did that, not once, but many times, and I let nature take its course. Do you know what happened, every single time?”