"How on earth did you ever get a hint of such a thing as this?" said Beatrice.
"Weems' watch gave a pointer. It was all right, the jeweler said, but it wouldn't run. Well, it did run—but at a speed so slow that it could not be recorded. The roulette wheel was another. The ivory ball did not roll down the side of the wheel because the wheel was rotating—with infinite slowness after being retarded by the same thing that made the people look like frozen statues. Satan, as Madame Sin, couldn't do anything about the wheel. But he—or 'she'—could and did take the watches from all concerned, to guard against discovery that way. However, there was no chance to get Weems' watch; there were always people around."
"You said Doctor Satan moved in the body of Chichester as he did in the girl's body."
"Yes. I got a hint of that when I observed that Chichester and Madame Sin never seemed to be in evidence at the same time. Also because the exact sum of Blue Bay's cash reserve was so readily learned. Again when Wilson was killed in a room where only the three officials sat. He was killed by Chichester, who was at the moment animated by Satan's soul. He was killed, by the way, by a speeding-up of time. The rest were retarded and suffered nothing but nerve shock. Wilson was killed when the speed of his time-stream was multiplied by a million: you can stop a heart without injuring it, but you can't suddenly accelerate a heart, or any other machine, a million times, without bursting it. That's why his heart looked as though it had blown up in his chest."
Keane stopped. The bitter look grew in his eyes.
"This failure was wholly my own fault," he said in a low tone. "I knew when I found the duplicate financial statement in Madame Sin's rooms that it was a trap to draw me to Chichester's home. Doctor Satan would never have been so careless as to leave a thing like that behind inadvertently. Knowing it was a trap, I entered it, and found Satan's soulless body. If I'd destroyed it immediately.... But I didn't dream that Madame Sin would follow me so quickly."
Beatrice's hand touched Keane's fleetingly. He was looking at the geometric figure and did not see the look in her eyes.
"The world can thank heaven you're alive," she said softly. "With you dead, Doctor Satan could rule the earth——"
There was a knock at the door. Gest was in the hall.