The crook appraised the apparatus calmly. He displayed not a trace of excitement now, but Mortenson's blood pounded at his temples. He did not object to handing over his instruments, if they were to cause justice to place the hand of doom on the man who was robbing him and who had and would rob others. Within ten days he could construct other sets. The plans were in a safe-deposit vault in the bank. Mortenson was nobody's fool, though it had not entered his mind when he gave the _Journal_ editor the interview, that his inventions would ever fall into the hands of the underworld. He was vaguely sorry now that he had allowed the news to be published, but it was too late for regret now. The thing was done. "There you are, young fellow," he said, placing the apparatus in a heap on the bench. "Take it and be damned to you!" "I didn't figure to get it so easy," the crook said, advancing toward the bench. "I've got a hunch you're trying to be smart!" He glared at the scientist evilly, his fiery eyes glittering like the pink orbs of a snake. "How do you put this stuff on?" he added with a snap. "Helmet over the head, cylinders in front at the eyes," said Mortenson, hiding a grin. "Belt around the waist with attachment at the back. Plug the wires into the oval unit and send yourself into hell!" "Funny, aren't you?" the fellow growled. "Is that all?" "Wait and see!" Mortenson mused. "If you're pulling a fast one ... here! Take this to remember what'll happen to you if you are!" The crook stepped forward suddenly. Before Mortenson had time to move the automatic crashed with a thud on his head. He sank to the floor with a groan, a terrible roar in his brain, great, dancing lights spinning before his dazed eyes. The intruder looked at him once, stepped over the still body and picked up the apparatus. With a pleased grin he made for the door and vanished into the night. II _The Robbery_ When Professor Jerome Mortenson regained his senses a midday sun was casting its brilliant light and warmth through a skylight directly over him. His head throbbed painfully, his lips were dry and feverish. Dark stains on his shirt-front made him feel his aching head. His hair was matted with coagulated blood, his cheek was caked. He marvelled that he had survived the terrible blow at all. Half-dazed he stood up, swaying like a drunken man. The room spun like a top. He closed his eyes to steady himself, then lurched slowly toward a wash-stand to douse his head in cold water. A trickle of vermilion ran down his temple after the dried blood had been washed from a gaping scalp wound that would require at least three stitches to close. Holding a towel over the gash he sat down to his telephone, called a doctor, and waited in gloomy silence for his arrival.