Knowing that the number of the four-wheeler was 872, it was not a difficult matter to begin the inquiry. But to secure any real information—that was different. The driver, a respectable albeit somewhat thick-headed Irishman, could offer only vague recollections of his business for the night of November 16th. He had been lucky enough to secure several fares, but there had been nothing in the appearance of any of his passengers to attract his attention. A gentleman in evening dress with his head tied up in a black bag and accompanied by a man wearing a red fez! Certainly he would have taken notice of anything like THAT. "Niver in my cab," asseverated honest Mulvihill. "I've been hacking it for twenty years and carried some quare cargoes. But of that sort—no, sorr!"

Clearly there was nothing to be learned from the cabman, and he was undoubtedly sincere in his protestations. The little peculiarities of costume that had originally caught my eye were obviously unsuited for public wear. The fez and the black bag had probably been brought into use after the men of mystery had entered the cab, and it was only through the accident of the suddenly released window-shade that Esper Indiman and I had seen what we did. "No thoroughfare" stood out plainly on this particular road. Then the humor took me to try conclusions with Chance herself, the method a la Indiman. I chucked a silver dollar to the cabman. "Whatever it's worth to you in time and distance," I said. "Don't ask me any questions—go as you please."

Hackman Mulvihill was a humorist in his way and he wanted to spare his horse. Six times in succession we made the circuit of Madison Square and never once off the walk. I was on the point of protesting, but I remembered the rules of the game and held my tongue. Finally, we started down-town by way of Fourth Avenue. Near Sixteenth Street and Union Square the cab pulled up to the curb, an intimation that my chartered voyage was over.

"And now which way?" I inquired, smilingly.

Mr. Mulvihill regarded me with compassionate and somewhat unflattering interest. "Be glory!" he said, frankly, "it's Bellevue that ye'll be wanting afore long, and badly, too. Come, now, jist jump in again and I'll rowl ye up there quiet and peaceable like. A touch of liver, sorr. I know how it takes them. Maning a drop too much of the 'red-eye,'" he added, under his breath. "Quiet, there, Noddy, ye black divil."

It was with some difficulty that I convinced this good Samaritan of my mental and physical equilibrium. Finally he drove off, wagging his head doubtfully.

"But which way?" I shouted after him. He would not answer in words, but pointed eastward with his whip-stock. Eastward then it was.

Between Union Square and Second Avenue there are several blocks of dwelling-houses—a once fashionable and still highly respectable residential neighborhood. The particular street does not matter, but I was proceeding in the general direction of Stuyvesant Square and had crossed Third Avenue.

Being on the lower or shady side it was something of a surprise to receive a flash of sunlight directly in the eye. I stepped back. On the pavement at my feet there floated a blot of quivering yellow light; it danced directly towards me, and again I was blinded by its dazzle.

The reflection from a mirror, of course, but it took me several minutes to determine its location.