"Why?"

"We don't know. It happened almost eight thousand years ago. I suspect they ran out of game because of overhunting, and no doubt the climate had something to do with it."

"I don't like that one," Veg said. "These builders didn't have to hunt for a living. If something happened to them, it sure could happen to us."

"On the other hand, they could be here now, sleeping -- or watching us."

"I don't like that, either," Veg said.

"Or perhaps this is a prison city, made for the confinement of enemies or undesirables until sentence is p.r.o.nounced."

"You get worse as you go," Veg said, grimacing. "You try it, 'Quilon."

Aquilon smiled. That still gave him a nervous thrill, for he remembered when she could not smile back on Planet Nacre. In certain ways things had been better then. "How about a vacation resort for honored guests?"

"Stop there," he said. "I like it."

"At any rate," Cal concluded, "whatever brought us can certainly remove us -- and will when it so chooses. We would do well to conduct ourselves decorously."

"Segregation of the s.e.xes?" Aquilon asked mischievously.

"He means not to break anything," Veg said -- and realized too late that no one had needed any interpretation. Neither girl was stupid; Veg himself was the slow member of the group. It had never bothered him when they were three; now that they were four, it somehow did.

"You understand that, mantas?" Aquilon asked. "We don't want trouble."

The two fungoids agreed with token snaps of their tails. Aquilon had, in her way, taken the sting from his verbal blunder, for the mantas did need to have human dialogue clarified on occasion. Still the sweet girl, 'Quilon, and he loved her yet -- but not in the same way as before. Oh, if certain things could be unsaid, certain mistakes taken back... but what was the use in idle speculation? In time love would diminish into friendship, and that was best.

"For now, let's rest," Tamme said.

Rest! Veg knew Tamme didn't need it half as much as the others did. The agents were tough, awfully tough. And in their fashion, intriguing.

Cal nodded agreement. He would be the most tired. He was much stronger than he had been when Veg met him back in s.p.a.ce before Nacre, and now he could eat ordinary foods, but still his physical resources were small. "The mantas will stand guard," Cal said.

Tamme gave no indication, but somehow Veg knew she was annoyed. She must have planned to scout around alone while the others slept; maybe she had some secret way to contact the agents back on Paleo. But she could not conceal it from the mantas!

Then Tamme looked directly at him, and Veg knew she knew what he was thinking. Embarra.s.sed, he curtailed his conjectures. And Tamme smiled faintly. b.i.t.c.h! he thought, and her smile broadened.

They found places around the chamber. The benches were surprisingly comfortable, as though cushioned, yet the material was hard. Another trick of the city's technology? But there was one awkward problem.

"The john," Aquilon said. "There has to be one!"

"Not necessarily," Cal replied, smiling in much the way Tamme had. "Their mores may differ from ours."

"If they ate, they sat," Veg said firmly. "Or squatted. Sometime, somewhere, somehow. No one else could do it for them."

"They could have designed machines to do it for them."

Veg had a vision of a machine slicing a person open to remove refuse. "Uh-uh! I wouldn't tell even a machine to eat -- "

"A variant of dialysis," Cal continued. "I have been dialyzed many times. It is simply a matter of piping the blood through a filtration network and returning it to the body. Painless, with modern procedures. It can be done while the subject sleeps."

"I don't want my blood piped through a machine!" Veg protested. "Now I'll be afraid to sleep for fear a vampire machine will sneak up on me, ready to beat the oomph out of me!"

"Dialysis would only account for a portion of it," Aquilon murmured.

"Oh, the colon can be bypa.s.sed, too," Cal a.s.sured her.

Veg did not enjoy this discussion. "What say we set aside a place, at least until we find a real privy? In fact, I can make a real privy."

Cal spread his hands in mock defeat. "By all means, Veg!"

"I will forage for building materials," Tamme offered.

"I'll help," Aquilon said. "Circe?"

"That is kind of you," Tamme said. Veg wondered whether she meant it. Foraging alone, the female agent could have explored the city widely and maybe made her report to Taler. Now she couldn't -- and even if she moved out too quickly for Aquilon to follow, the manta would keep her in sight. Smart girl, 'Quilon!

Then he glanced at Tamme to see whether she were reading his reactions again. But she was not watching him this time, to his relief.

His eyes followed as the two women departed. How alike they were, with their blonde hair and shapely bodies -- yet how unlike! Would they talk together? What would they say? Suddenly he was excruciatingly curious. Maybe he could find out from Circe later.

"I think you need no warning," Cal said quietly as he poked about the suspended stage. "Just remember that girl is an agent, with all that implies."

Veg remembered. Back on Earth the agents had moved in to destroy every vestige of manta penetration. They had burned Veg's northern forest region, ga.s.sed the rabbits and chickens of the cellar-farm in Aquilon's apartment complex, and bombed the beaches where Cal had lived. Then they had come to Paleo and brutally exterminated the dinosaurs. That memory was still raw -- but years would never completely erase the pain of it.

They were agents of what Aquilon called the omnivore: man himself, the most ruthless and wasteful killer of them all. He knew, how well he knew!

Yet -- Tamme was a mighty pretty girl.

"Once we had a difference of opinion," Cal said. "I hope that does not occur again."

Veg hoped so, too. He and Aquilon had argued against making any report on the alternate world of Paleo, to protect it from the savage exploitation of man. Cal had believed that their first loyalty had to be to their own world and species. Their difference had seemed irreconcilable, and so they had split: Cal on one side, Veg and Aquilon on the other. And it had been a mistake, for Cal had in the end changed his mind, while the other two had only learned that they were not for each other. Not that way, not as lovers, not against Cal.

This time there was no question: They were all three against the omnivorous government of Earth. The agents were incorruptible representatives of that government, fully committed to their computer-controlled program. In any serious choice, Veg knew his interests lay with Cal and Aquilon, not with Tamme.

Yet it had not worked out with Aquilon, and Tamme was a pretty girl...

"It is possible to divorce the physical from the intellectual," Cal said.

G.o.d, he was smart -- as bad in his way as Tamme was in hers. "I'll work on it," Veg agreed.

They built the privy and also a little human shelter of light-cloth from the fountain-loom. It seemed ridiculous to pitch such a tent inside the doomed auditorium -- but the city was alien, while the shelter seemed human. It served a moral purpose rather than a physical one.

The mantas found meat somewhere while the humans ate the fruits. Survival was no problem. Veg conjectured that there were either rats or their equivalent in the city: omnivores for the mantas to hunt. Maybe no coincidence.

But as they ranged more widely through the city, they verified that there was no escape. The premises terminated in a yawning gulf whose bottom they could neither see nor plumb. This was, indeed, a prison. Or at least a detention site.

"But we were not brought here for nothing," Cal insisted. "They are studying us, perhaps. As we might study a culture of bacteria."