After half an hour the N.P.A.'s voice wasn't so sure. He had given Jon three more pills, had tried all the devices at the command of the largest neural-clinic in the Empire without the slightest effect. Jon Saxon continued to regard the N.P.A. with a half hidden gleam of amusement in his dark gray eyes. The neuro-psychoanalyst sat back, mopped his perspiring face with his handkerchief. "It's no use!" he said in a strained voice. "He can't be hypnotized!" "I could have told you that," replied Saxon. "Do you think I haven't tried to have the block broken before?" The N.P.A. swore and got to his feet. "Well, why didn't you say so?" he shouted. It was the first time Saxon had ever seen him lose his temper. "Because these gentlemen have been suspicious of me." He indicated Murdock and Villainowski. "If I had offered any objections to being hypnotized, they'd have been sure that I was afraid to." All at once, Saxon experienced the peculiar tingling in scalp and skin that warned him the alien creatures, whom he had met in the street, were present. He couldn't possibly be mistaken. Once having experienced that peculiar inhuman feel it was not to be forgotten or confused. Not only were they invisible, but neither doors nor walls seemed to offer any resistance to them. "_Who are you?_" he concentrated, but his thought met that strange mental barrier. There was no answer. He realized that the three men were watching him with a curious tenseness. Suddenly the N.P.A.'s jaw dropped. An expression of complete astonishment lit up his face. "I've got it! I've got it!" he cried. "Got what?" growled Villainowski, moving uneasily behind his massive desk. "Saxon! Saxon, that's who! My Lord, why didn't it occur to me before. He's a--" The words died suddenly on the N.P.A.'s lips. An expression of fright crossed his lean features. Then, without a sound, he crumpled to the carpet. Jon Saxon, staring in horror, realized that the tingling of his skin was diminishing. The telepaths were withdrawing. At the same instant Murdock's chair hit the floor as he leaped across the room, dropped to his knee beside the prone figure of the N.P.A. For a moment he was bent over the body like a bronze statue, then he turned his face up to Villainowski. Saxon, who had read his thoughts, was amazed at Murdock's passionless expression. "He's dead," the T.I.S. agent said in a toneless voice. "I wouldn't have believed it, if I hadn't seen it happen, but he's deader than the moon." IV Bong! Bong! Bong! Bong! rang the warning gong, reverberating through the launching pit. Mustapha IX had shaken hands for the last time with Villainowski and hurried down the gangplank. The ports were all sealed; crew at their stations. Outside the pits, the frenzied crowd was delirious with excitement. Wasn't it man's first attempt to reach the stars? Bong! Bong! Bong! Bong! Bong!