“Exactly,” we both murmured.  By two curves of the pencil, and a shock of false hair, the face was transmuted.

“He had very large eyes, with very big pupils, though,” I objected, looking close; “and the man in the photograph here has them small and boiled-fishy.”

“That’s so,” the Commissary answered.  “A drop of belladonna expands—­and produces the Seer; five grains of opium contract—­and give a dead-alive, stupidly-innocent appearance.  Well, you leave this affair to me, gentlemen.  I’ll see the fun out.  I don’t say I’ll catch him for you; nobody ever yet has caught Colonel Clay; but I’ll explain how he did the trick; and that ought to be consolation enough to a man of your means for a trifle of five thousand!”

“You are not the conventional French office-holder, M. le Commissaire,” I ventured to interpose.

“You bet!” the Commissary replied, and drew himself up like a captain of infantry.  “Messieurs,” he continued, in French, with the utmost dignity, “I shall devote the resources of this office to tracing out the crime, and, if possible, to effectuating the arrest of the culpable.”

We telegraphed to London, of course, and we wrote to the bank, with a full description of the suspected person.  But I need hardly add that nothing came of it.

Three days later the Commissary called at our hotel.  “Well, gentlemen,” he said, “I am glad to say I have discovered everything!”

“What?  Arrested the Seer?” Sir Charles cried.

The Commissary drew back, almost horrified at the suggestion.

“Arrested Colonel Clay?” he exclaimed.  “Mais, monsieur, we are only human!  Arrested him?  No, not quite.  But tracked out how he did it.  That is already much—­to unravel Colonel Clay, gentlemen!”

“Well, what do you make of it?” Sir Charles asked, crestfallen.

The Commissary sat down and gloated over his discovery.  It was clear a well-planned crime amused him vastly.  “In the first place, monsieur,” he said, “disabuse your mind of the idea that when monsieur your secretary went out to fetch Señor Herrera that night, Señor Herrera didn’t know to whose rooms he was coming.  Quite otherwise, in point of fact.  I do not doubt myself that Señor Herrera, or Colonel Clay (call him which you like), came to Nice this winter for no other purpose than just to rob you.”

“But I sent for him,” my brother-in-law interposed.

“Yes; he meant you to send for him.  He forced a card, so to speak.  If he couldn’t do that I guess he would be a pretty poor conjurer.  He had a lady of his own—­his wife, let us say, or his sister—­stopping here at this hotel; a certain Madame Picardet.  Through her he induced several ladies of your circle to attend his séances.  She and they spoke to you about him, and aroused your curiosity.  You may bet your bottom dollar that when he came to this room he came ready primed and prepared with endless facts about both of you.”