while, but presently I perceived that he wasn’t searching over the body of the carpet, but around its edges. He seemed to be looking for a place where it was loose, for he went very slowly from tack to tack. Once I thought he had found it, for he came to a place where a tack was wanting, and ran his hand under eagerly. But in a moment he brought it out again empty.”

“So it couldn’t have been the diamond,” I remarked in perplexity.

“No, it couldn’t have been the diamond,” assented Godfrey, his eyes shining. “But Tremaine wasn’t done yet. Really, he’d make an admirable detective. I admired his methods—though they also gave me a clew to what he was looking for. He placed a chair just here, before this desk, just opposite the bedroom door—you’ll remember that Thompson also had a table and chair similarly placed.”

“Yes, I remember.”

“Then he sat down in the chair and began a minute scrutiny of the walls—first that one yonder—he went over it inch by inch until he came to the speaking-tube. Then he sprang up and opened it and peered inside; even holding a lighted match in—let us see,” and Godfrey also examined the tube. “It’s empty.”

“Yes,” I said. “I’ve used it once or twice, and it works all right.”

“Well, Tremaine wasn’t satisfied with that. He ran his hands along the top ledges of the doors, mounted a chair and peered above the windows—examined every nook and cranny. At last he gave it up, replaced things just as he had found them, glanced