With a cleverness which was almost excruciating, the Aliens had carefully selected a number of animals native to each world, and then constructed robot duplicates. So simple then to place the robots down on a world with a single Director, then wait ... for the humans to inhabit. Naturally the humans screened all the animals and scouted a planet pretty thoroughly before they set up a colony. Naturally their snares and their hunters caught no robots, and never found the deep-buried Alien Director. Then the humans relaxed and began to make homes, never realizing that in among the animals which gamboled playfully in the trees there was one which did not gambol, but watched. Never once noticing the monkey-like animals or the small thing like a rabbit which was a camera eye, or the thing like a rat which took chemical samples, or the thing like a lizard which cut wires. The Alien rumbled on through the snow, trembling so much now with ecstasy and anticipation that the suit which bore him almost lost its balance. He very nearly fell over before he stopped trembling, and then he contained himself. In a little while, a very little while, there would be time enough for trembling. * * * * * "They could've been here 'til the sun went out," Rush said, "and we never would've known." "I wonder how much they've found out," Dylan said. Rush was holding the paw. "Pretty near everything, I guess. This stuff don't stop at monkeys. Could be any size, any kind ... look, let's get down into camp and tell 'em." Dylan rose slowly to a kneeling position, peering dazedly out into the far white trees. His mind was turning over and over, around and around, like a roulette wheel. But, at the center of his mind, there was one thought, and it was rising up slowly now, through the waste and waiting of the years. He felt a vague surprise. "Gettin' kind of dark," he said. Rush swore. "Let's go. Let's get out of here." He tugged once at Dylan's arm and started off on his knees. Dylan said: "Wait." Rush stopped. Through the snow he tried to see Dylan's eyes. The soldier was still looking into the woods. Dylan's voice was halting and almost inaudible. "They know everything about us. We don't know anything about them. They're probably sittin' out there right now, a swarm of 'em there behind those trees, waitin' for it to get real nice and dark." He paused. "If I could get just one." It was totally unexpected, to Dylan as well as Rush. The time for this sort of thing was past, the age was done, and for a long while neither of them fully understood. "C'mon," Rush said with exasperation. Dylan shook his head, marveling at himself. "I'll be with you in a little while." Rush came near and looked questioningly into his face.