"I erred," the robot acknowledged, with such a gleam in his eye that Martin, suddenly conscious of his rashness, jerked the helmet from his head and dropped it on the desk. ENIAC quietly picked it up and put it back into his sack, stuffing the red ribbon in after it with rapid motions. Martin watched, baffled, until ENIAC had finished, gathered together the mouth of the sack, swung it on his shoulder again, and turned toward the door. "Good-bye," the robot said. "And thank you." "For what?" Martin demanded. "For your cooperation," the robot said. "I won't cooperate," Martin told him flatly. "It's no use. Whatever fool treatment it is you're selling, I'm not going to--" "Oh, you've already had the ecology treatment," ENIAC replied blandly. "I'll be back tonight to renew the charge. It lasts only twelve hours." "_What!_" ENIAC moved his forefingers outward from the corners of his mouth, sketching a polite smile. Then he stepped through the door and closed it behind him. Martin made a faint squealing sound, like a stuck but gagged pig. _Something was happening inside his head._ II Nicholas Martin felt like a man suddenly thrust under an ice-cold shower. No, not cold--steaming hot. Perfumed, too. The wind that blew in from the open window bore with it a frightful stench of gasoline, sagebrush, paint, and--from the distant commissary--ham sandwiches. "Drunk," he thought frantically. "I'm drunk--or crazy!" He sprang up and spun around wildly; then catching sight of a crack in the hardwood floor he tried to walk along it. "Because if I can walk a straight line," he thought, "I'm not drunk. I'm only crazy...." It was not a very comforting thought. He could walk it, all right. He could walk a far straighter line than the crack, which he saw now was microscopically jagged. He had, in fact, never felt such a sense of location and equilibrium in his life. His experiment carried him across the room to a wall-mirror, and as he straightened to look into it, suddenly all confusion settled and ceased. The violent sensory perceptions leveled off and returned to normal. Everything was quiet. Everything was all right. Martin met his own eyes in the mirror. Everything was _not_ all right. He was stone cold sober. The Scotch he had drunk might as well have been spring-water. He leaned closer to the mirror, trying to stare through his own eyes into the depths of his brain. For something extremely odd was happening in there. All over his brain, tiny shutters were beginning to move, some sliding up till only a narrow crack remained, through which the beady little eyes of neurons could be seen peeping, some sliding down with faint crashes, revealing the agile, spidery forms of still other neurons scuttling for cover. Altered thresholds, changing the yes-and-no reaction time of the memory-circuits, with their key emotional indices and associations ... huh? The robot!