During the performance the audience smoke and sip.  Between the acts most of them swarm out into the adjacent corridors leading to the gaming-rooms,—­licensed rooms these, with toy-horses ridden by tin jockeys, and another equally delusive and tempting device of the devil—­a game of tipsy marbles, rolling about in search of sunken saucers emblazoned with the arms of the nations of the earth.  These whirligigs of amateur crime are constantly surrounded by eager-eyed men and women, who try their luck for the amusement of the moment, or by broken-down, seedy gamblers, hazarding their last coin for a turn of fortune.  Now and then, too, some sweet-faced girl, her arm in her father’s, wins a louis with a franc, her childish laughter ringing out in the stifling atmosphere.

* * * * *

The Tyrolean warbler had just finished her high-keyed falsetto, bowing backward in her short skirts and stout shoes with silver buckles, and I had just reached the long corridor on my way to the garden, to escape the blare and pound of the band, when a man leaned out of a half-opened door and touched my shoulder.

“Pardon, monsieur.  May I speak to you a moment?”

He was a short, thick-set, smooth-shaven, greasy man, dressed plainly in black, with a huge emerald pin in his shirt front.  I have never had any particular use for a man with an emerald pin in his shirt front.

“There will be a game of baccarat,” he continued in a low voice, his eyes glancing about furtively, “at eleven o’clock precisely.  Knock twice at this door.”

Old habitues of Lucerne—­habitues of years, men who never cross the Alps without at least a day’s stroll under the Noah’s-ark trees,—­will tell you over their coffee that since the opening of the St. Gotthard Tunnel this half-way house of Lucerne—­this oasis between Paris and Rome—­has sheltered most of the adventurers of Europe; that under these same trees, and on these very benches, nihilists have sat and plotted, refugees and outlaws have talked in whispers, and adventuresses, with jeweled stilettos tucked in their bosoms, have lain in wait for fresher victims.

I had never in my wanderings met any of these mysterious and delightful people.  And, strange to say, I had never seen a game of baccarat.  This might be my opportunity.  I would see the game and perhaps run across some of these curious individuals.  I consulted my watch; there was half an hour yet.  The man was a runner, of course, for this underground, unlicensed gaming-house, who had picked me out as a possible victim.

When the moment arrived I knocked at the door.