He lifted the ball from the sloping side of the wheel. It came away freely, but with an almost intangible resistance, as if an unseen rubber band held it. When he released it, it went back to the slope. He rolled it down to the bottom of the wheel. Released, it rolled back up to its former position, like water running up-hill. Keane felt a chill touch him. The laws of physics broken! A ball clinging to a slant instead of rolling down it! What dark secret of nature had Doctor Satan mastered now? But the query was not entirely unanswered in his mind. Already he was getting a vague hint of it. And a little later the hint was broadened. The phone rang. He answered it. "Mr. Keane? This is Doctor Grays. The autopsy on Wilson has been begun, and already a queer thing has been disclosed. It's about his heart." "Yes," said Keane, gripping the phone. "His heart is ruptured in a hundred places--as though a little bomb had exploded in it! Don't ask me why, because I can't even give a theory. It's unique in medical history." "I won't ask you why," Keane said slowly. "I think--in a little while--I'll tell you why." He hung up and strode toward the door. But at the roulette table he paused and stared at the wheel with his gray eyes icily blazing. _It seemed to him the wheel had moved a little!_ He had unconsciously lined up the weirdly clinging ball with the knob on the outer door, as he examined it awhile ago. Now, as he stood in the same place, the ball was not quite in that line. As if the wheel had rotated a fraction of an inch! "Yes, I think that's it," he whispered, with his face a little paler than usual. And a little later the words changed in his brain to: "I _know_ that's it. A fiend's genius.... This is the most dangerous thing Doctor Satan has yet mastered!" He was talking on the phone to the jeweler to whom Weems' watch had been sent. "What did you do to that watch?" the jeweler was saying irritably. "Why?" parried Keane. "There doesn't seem to be anything wrong with it. And yet it simply won't go. And I can't make it go." "There's nothing wrong with it at all?" "As far as I can find out--no." * * * * * Keane hung up. He had been studying for the dozenth time the demand note Doctor Satan had written the officials: