We had almost left the hotel—we were on the outside steps, indeed—when the hall porter caught me up. I saw at once what he was carrying. It was one of the now familiar typewritten letters. This time I asked him a point-blank question.

"Look here," I said, with my hand in my trousers pocket, "this is the third note I have received from my friend in this fashion. I want to know how they come into your possession. Who leaves them at the bureau?"

The man saw the ten-shilling note in my hand but he only shook his head. I believe that he was perfectly honest.

"I would tell you in a minute if I knew, sir," he declared, "but to tell you the truth I have never seen one delivered. All three I have picked up from the desk in my office, evidently left there when my back was turned for a moment."

"You haven't any idea who leaves them there, then?" I persisted.

"Not the slightest, sir," the man assured me.

"Keep a good lookout," I begged him, "and let me know if you do find out. There may be another one—I can't tell—but I'll double this ten shillings if you succeed."

The man thanked me and withdrew. We three crossed to the less frequented side of the road. I walked in the middle, with Rose and Leonard on either arm. We read the note together:

If the box Miss Mindel saw in Kinlosti's room was of purple leather, with gold clasps and corners, let the first item in your repertoire to-night be the Missouri Waltz. If it was a box of any other description, play the selection from "Chu-Chin-Chow."

"Well, I'm damned!" Leonard exclaimed.