I knew perfectly well it was what he had intended to do all along.

"One of you guys spin that wheel," he said to the technicians. One of them gave the wheel a spin and dropped the ball. It clattered on its merry way and dropped into a slot. Forty-two.

Thursby took the gadget out of his pocket. It was still set at Thirteen.

The men who had surrounded Howley on the night of his arrest had been keeping their eyes open, and they had seen how Howley had handled the thing. Well—almost how. Thursby had the lens opening pointed at the wheel, but his thumb and fingers weren't touching the silver plates properly.

"Spin it again," he said.

Everyone's eyes were on the ball as it whirled, so I had time to get my own copy of Howley's gadget out and set it at Thirteen. I hoped the thing would work for me. I concentrated on Thirteen, making sure my thumb and fingers were placed right.

Evidently they were. The ball fell into Thirteen, Black, Odd, and Low.

A huge grin spread over Thursby's face, but he was man enough not to turn and grin at me. "Try it again," he said.

Thirteen, Black, Odd, and Low.

"I wonder how the thing works?" said Thursby, looking at the gadget in a sort of pleased awe.