“Right.”

“Then—whose?”

“If you are too dull to have read your own sound clues, Ear Detective, far be it from me to dull your wits by telling. Think!”

Presently Millman, Zendt, Ellison, Hope and several other staff men, in pairs or alone, arrived. They were eager, excited as they questioned. Grover, picking Roger’s list of clues out of his file, presented it and suggested that what he had learned they could learn, while Roger recounted his own experiences up to date.

That was done; and they pored over his list. Grover, getting a lot of amusement out of their guesses, chuckled to himself; but his younger cousin felt that he was watching them to see when the guilty one would crack and admit that he was cornered.

Who, besides, could be guilty? Doctor Ryder was in hospital; so was Astrovox. So, in jail, Toby Smith was out of the night’s excitement.

To his amazement, a police car, arriving, brought an officer who brought in the last captive he had been thinking about—Toby.

The men seemed to have found no light in Roger’s list.

Roger, who had heard their sane, or wild surmises, suddenly sat up.

Some brain cell, stimulated by the continual stress of cogitation, spoke its concealed message.