I whistled softly to myself.  I began to see Louis’ idea.  I was to enter, somehow or other, the room in which Mr. Delora was supposed to be, to remain there concealed, and to await this attack which, for some reason or other, they were expecting.  And then, as the possibilities connected with such an event spread themselves out before me, my sense of humor suddenly asserted itself, and, to Louis’ amazement, I laughed in his face.  I came back from this world of fanciful figures, of mysterious robberies, of attempted assassinations, to the world of every-day things.  It was Louis—­the maitre d’hotel, the man who had ordered my Plat du Jour and selected my Moselle—­who spoke of these things so calmly in my own sitting-room, with a menu card in his hand, and a morocco-bound wine list sticking out of his breast pocket.  I was not in any imaginary city but in London,—­city of tragedies, indeed, but tragedies of a homelier sort.  It was not possible that such things could be happening here, in an atmosphere which, through familiarity, had become almost commonplace.  Was I to believe that Louis, my favorite maitre d’hotel, my fellow schemer in many luncheon and dinner parties, my authority upon vintages, my gastronomic good angel, was one of a band of conspirators, who played with life and death as though they had been the balls of a juggler?  Was I to believe that there existed even in this very hotel, which for years had been my home, the seeds of these real tragical happenings which sometimes, though only half disclosed, blaze out upon the world as a revelation of the great underground world of crime?  I found it almost impossible to take Louis seriously.  I could not focus my thoughts.

“Louis,” I said, “is this a great joke, or are you talking to me in sober, serious earnest?”

“I am talking in earnest, monsieur,” Louis said slowly.  “I have not exaggerated or spoken a word to you which is not the truth.”

“Let me understand this thing a little more clearly,” I said.  “What has Ferdinand Delora done that he need fear a murderous assault?  What has he done to make enemies?  Is he a criminal, or are those who seek him criminals?”

“He carries with him,” Louis said slowly, “a secret which will produce a great fortune.  There are others who think that they have a right to share in it.  It is those others who are his enemies.  It is those others who hope to attain by force what they could gain by no other means.”

A sudden inspiration prompted my next question.

“Was Tapilow one of those?” I demanded.

Louis nodded gravely.

“Monsieur Tapilow was one of those who claimed a share, but he was not willing to run the smallest risk,” he assented.

“And for that reason,” I remarked, “he is well out of the way!  I understand.  There is one more question, Louis, and it is one which you must answer me truthfully.  You can imagine what it is when I tell you that it concerns mademoiselle!”