Godfrey nodded. "That," he said, "explains the one thing I didn't understand. Now go ahead with your questions." "You said a while ago that you would know all about this affair day after to-morrow." "Yes." "How do you know you will?" "Because I have received a letter which sets the date," and he took from his pocket a sheet of paper and handed it over to me. "Read it!" The letter was written in pencil, in a delicate and somewhat feminine hand, on a sheet of plain, unruled paper. With an astonishment which increased with every word, I read this extraordinary epistle:-- "_My Dear Mr. Godfrey:_ "I have been highly flattered by your interest in the affaire of the cabinet Boule, and admire most deeply your penetration in arriving at a conclusion so nearly correct regarding it. I must thank you, also, for your kindness in keeping me informed of the measures which have been taken to guard the cabinet, and which seem to me very complete and well thought out. I have myself visited the station and inspected the cell, and I find that in every detail you were correct. "It is because I so esteem you as an adversary that I tell you, in confidence, that it is my intention to regain possession of my property on Wednesday next, and that, having done so, I shall beg you to accept a small souvenir of the occasion. "I am, my dear sir, "Most cordially yours, "JACQUES CROCHARD, "L'Invincible!" I looked up to find Godfrey regarding me with a quizzical smile. "Of course it's a joke," I said. Then I looked at him again. "Surely, Godfrey, you don't believe this is genuine!" "Perhaps we can prove it," he said, quietly. "That is one reason I came up. Didn't Armand leave a note for you the day he failed to see you?" "Yes; on his card; I have it here!" and with trembling fingers, I got out my pocket-book and drew the card from the compartment in which I had carefully preserved it. One glance at it was enough. The pencilled line on the back was unquestionably written by the same hand which wrote the letter. "And now you know his name," Godfrey added, tapping the signature with his finger. "I have been certain from the first that it was he!"