The automobile was speeding up the wide driveway that led to Tower Mansion, and within a few minutes it drew up at the front entrance. Mr. Applegate dismissed the driver, and Mr. Hardy and the two boys accompanied the eccentric man into the house.

Nothing had been disturbed in the library since the discovery of the theft. Mr. Hardy examined the open safe, then drew a magnifying glass from his pocket and with minute care inspected the dial of the combination lock. Then he examined the windows, the doorknobs, all places where there might be fingerprints. At last he shook his head.

“A smooth job,” he observed. “The fellow must have worn gloves. Not a fingerprint in the room.”

“No need of looking for fingerprints,” said Applegate. “It was Robinson⁠—that’s who it was.”