Norden tried to fight down his own panic. Surely it would be madness to doubt the outcome. But a doubt began to throb in his mind. He could remember so little. He'd thought the Aliens had never found him. But if they had actually captured him, tampered with his mind, and turned him back again, would he know it? Suppose he was an Alien--one given a spurious, hypnotic belief he was Norden until the right signal to become himself again.... It was ridiculous, absurd! But the speculations ran on in his tormented mind. He didn't belong here. Men apparently took it for granted that a confessed spy could keep his life--and Norden took it equally for granted that death was the only answer. He didn't think like the rest of them. There had been that week on the asteroid. His memories were spotty.... "Dr. William Norden!" the speaker announced. He shuddered convulsively. Then he caught himself, and forced his reluctant legs to move. The door shut behind him, and ahead lay the white square on which he was to stand. He approached the spot automatically, bracing himself to face straight ahead toward the fluoroscopic screen. _Now!_ It was almost a physical voice in his head. And his mind seemed to shift, to shout something down. _Not yet! Look!_ "Okay, Dr. Norden," the speaker said. His eyes flicked to the screen where a human skeleton showed dimly. Crazy, he told himself. Hagridden with fears no sane human mind could have endured and retained its sanity. No wonder the psychologists had been uncertain about him. Unbalanced--but human! Pat smiled weakly at him as he entered the room beyond, to join the ranks of the elect. Then they watched as their group passed successfully, to give place to a number of rocket men from the freight gang. The sixth rocket man came through the door boldly enough--and suddenly leaped toward the side of the chamber where another door was. His hands were jolting at the locked barrier when the rifles sounded. A violent blast of greenish-yellow explosion rocked the chamber and shook the floors beyond. When it cleared, the Alien was dust and vapor, with nothing that could be studied for evidence. Two workers who had been standing in line in a building beyond broke through the seal together, without waiting their turn, and headed with desperate haste for the shelter of a nearby barracks. A rifle bullet tore into one, and both exploded instantly. By the time the rest had been proved safe in a testing ordeal as grim as death, it was the hour for lunch--a shocked, silent interlude at first. Then one of the men caught sight of a neighbor busily shaking his fork, and glancing sideways to emphasize some point. A tiny gadget appeared, and was concealed quickly under the steak on the man's plate. Ten seconds later, when the man cut into the meat, there was a cowlike bellow and the meat leaped six inches up, and two feet sideways. There was a shout of laughter that grew into a roar, and everything was suddenly normal again.