“Pooh!” the Commissary answered.  “What would he be worth as a conjurer, anyway, if he couldn’t substitute one envelope for another between the table and the fireplace without your noticing it?  And Colonel Clay, you must remember, is a prince among conjurers.”

“Well, it’s a comfort to know we’ve identified our man, and the woman who was with him,” Sir Charles said, with a slight sigh of relief.  “The next thing will be, of course, you’ll follow them up on these clues in England and arrest them?”

The Commissary shrugged his shoulders.  “Arrest them!” he exclaimed, much amused.  “Ah, monsieur, but you are sanguine!  No officer of justice has ever succeeded in arresting le Colonel Caoutchouc, as we call him in French.  He is as slippery as an eel, that man.  He wriggles through our fingers.  Suppose even we caught him, what could we prove?  I ask you.  Nobody who has seen him once can ever swear to him again in his next impersonation.  He is impayable, this good Colonel.  On the day when I arrest him, I assure you, monsieur, I shall consider myself the smartest police-officer in Europe.”

“Well, I shall catch him yet,” Sir Charles answered, and relapsed into silence.

II

THE EPISODE OF THE DIAMOND LINKS

“Let us take a trip to Switzerland,” said Lady Vandrift.  And any one who knows Amelia will not be surprised to learn that we did take a trip to Switzerland accordingly.  Nobody can drive Sir Charles, except his wife.  And nobody at all can drive Amelia.

There were difficulties at the outset, because we had not ordered rooms at the hotels beforehand, and it was well on in the season; but they were overcome at last by the usual application of a golden key; and we found ourselves in due time pleasantly quartered in Lucerne, at that most comfortable of European hostelries, the Schweitzerhof.

We were a square party of four—­Sir Charles and Amelia, myself and Isabel.  We had nice big rooms, on the first floor, overlooking the lake; and as none of us was possessed with the faintest symptom of that incipient mania which shows itself in the form of an insane desire to climb mountain heights of disagreeable steepness and unnecessary snowiness, I will venture to assert we all enjoyed ourselves.  We spent most of our time sensibly in lounging about the lake on the jolly little steamers; and when we did a mountain climb, it was on the Rigi or Pilatus—­where an engine undertook all the muscular work for us.

As usual, at the hotel, a great many miscellaneous people showed a burning desire to be specially nice to us.  If you wish to see how friendly and charming humanity is, just try being a well-known millionaire for a week, and you’ll learn a thing or two.  Wherever Sir Charles goes he is surrounded by charming and disinterested people, all eager to make his distinguished acquaintance, and all familiar with several excellent