"He ran his finger down the list of names and had just turned to the account of one of the customers when we were startled by a loud click from the direction of the strong-room. We both turned sharply and beheld Thorndyke grasping the handle of the strong-room door, and I saw with amazement that the door was now slightly ajar. "God!" exclaimed Miller, shutting the ledger and starting forward, "he's got it open!" He strode over to the door, and directing an eager look at the indicator of the lock ...