We crowded out of the elevator at the fourth floor, and found ourselves in a rather theatrical hallway of draperies and armor. It was very quiet; we stood uncertainly after the car had gone, and looked at the two or three doors in sight. They were heavy, covered with metal, and sound proof. From somewhere above came the metallic accuracy of a player-piano, and through the open window we could hear—or feel—the throb of the Cannonball’s engine. “Well, Sherlock,” McKnight said, “what’s the next move in the game? Is it our jump, or theirs? You brought us here.” None of us knew just what to do next. No sound of conversation penetrated the heavy doors. We waited uneasily for some minutes, and Hotchkiss looked at his watch. Then he put it to his ear. “Good gracious!” he exclaimed, his head cocked on one side, “I believe it has stopped. I’m afraid we are late.” We _were_ late. My watch and Hotchkiss’ agreed at nine o clock, and, with the discovery that our man might have come and gone, our zest in the adventure began to flag. McKnight motioned us away from the door and rang the bell. There was no response, no sound within. He rang it twice, the last time long and vigorously, without result. Then he turned and looked at us. “I don’t half like this,” he said. “That woman is in; you heard me ask the elevator boy. For two cents I’d—” I had seen it when he did. The door was ajar about an inch, and a narrow wedge of rose-colored light showed beyond. I pushed the door a little and listened. Then, with both men at my heels, I stepped into the private corridor of the apartment and looked around. It was a square reception hall, with rugs on the floor, a tall mahogany rack for hats, and a couple of chairs. A lantern of rose-colored glass and a desk light over a writing-table across made the room bright and cheerful. It was empty. None of us was comfortable. The place was full of feminine trifles that made us feel the weakness of our position. Some such instinct made McKnight suggest division. “We look like an invading army,” he said. “If she’s here alone, we will startle her into a spasm. One of us could take a look around and—” “What was that? Didn’t you hear something?” The sound, whatever it had been, was not repeated. We went awkwardly out into the hall, very uncomfortable, all of us, and flipped a coin. The choice fell to me, which was right enough, for the affair was mine, primarily. “Wait just inside the door,” I directed, “and if Sullivan comes, or anybody that answers his description, grab him without ceremony and ask him questions afterwards.”