to Paris from a stay at her chateau in Normandy to find that he had almost denuded the town house.  Tapestries, pictures, sculptures—­everything had been sold.  Among other things which he had taken was a Boule cabinet, which had been used by my client as her private writing-desk.  The cabinet was a most valuable one; but it is not its monetary value which makes my client so anxious to recover it.”

He paused an instant and cleared his throat, and I realised that he was coming to the really delicate part of the story.

“Monsieur X. had had the decency,” he went on, more slowly, “to, as he thought, retain his wife’s private papers.  He had caused the contents of the various drawers to be dumped out upon a chair.  But there was one drawer of which he knew nothing—­a secret drawer, known only to my client.  That drawer contained a packet of letters which my client is most anxious to regain.  Of their nature, I will say nothing—­indeed, I know very little about them, for, after all, that is none of my business.  But she has given me to understand that their recovery is essential to her peace of mind.”

I nodded again; there was really no need that he should say more.  Only, I reflected, a faithless husband has no reason to complain if his wife repays him in the same coin!

“My client went to work at once to regain the cabinet,” continued Mr. Hornblower, plainly relieved that the thinnest ice had been crossed.  “She found that it had been sold to Armand & Son.  Hastening to their offices, she learned that it had been resold by them to Mr. Vantine and sent forward to him here.  So she came over on the first boat, ostensibly to visit her family, but really to ask Mr. Vantine’s permission to open the drawer and take out the letters.  His death interfered with this, and, in despair, she came to me.  I need hardly add, that no member of her family knows anything about this matter, and it is especially important that her husband should never even suspect it.  On her behalf, I apply to you, as Mr. Vantine’s executor, to restore these letters to their owner.”

I sat for a moment turning this extraordinary story over in my mind, and trying to make it fit in with the occurrences of the past two days.  But it would not fit—­at least, it would not fit with my theory as to the cause of those occurrences.  For, surely, Madame X. would scarcely guard the secret of that drawer with poison!

“Does any one besides your client know of the existence of these letters?” I asked, at last.

“I think not,” answered Mr. Hornblower, smiling drily.  “They are not of a nature which my client would care to communicate to any one.  In fact, Mr. Lester, as you have doubtless suspected, they are compromising letters.  We must get them back at any cost.”

“As a matter of fact,” I pointed out, “there are always at least two people who know of the existence of every letter—­the person who writes it and the person who receives it.”