“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!”

I gazed at the signature without answering.  I had, of course, read in the papers many times of the Gargantuan exploits of Crochard—­“The Invincible,” as he loved to call himself, and with good reason.  But his achievements, at least as the papers described them, seemed too fantastic to be true.  I had suspected more than once that he was merely a figment of the Parisian space-writers, a sort of reserve for the dull season; or else that he was a kind of scape-goat saddled by the French police with every crime which proved too much for them.  Now, however, it seemed that Crochard really existed; I held his letter in my hand; I had even talked with him—­and as I remembered the fascination, the finish, the distinguished culture of M. Felix Armand, I understood something of the reason of his extraordinary reputation.

“There can be no two opinions about him,” said Godfrey, reaching out his hand for the letter and sinking back in his chair to contemplate it.  “Crochard is one of the greatest criminals who ever lived, full of imagination and resource, and with a sense of humour most acute.  I have followed his career for years—­it was this fact that gave me my first clue.  He killed a man once before, just as he killed this last one.  The man had betrayed him to the police.  He was never betrayed again.”