Shirley endured a miserable three hours, in his attempts to locate the girl.  She had not returned to the Hotel California, and he returned to the club in moody reflection.  It was beginning to snow, and the ground was soon covered with a thin coat of white, through which he noticed his footprints stenciled against the black of the wet pavement.  He wasted a dozen matches in the freshening wind, as he tried to light a cigarette.  He stepped into a doorway on the Avenue to avail himself of its shelter.  As he turned out to the street again, he almost bumped into two men, wearing black caps!  One of them grunted a curt apology, as he stepped on.

“They are after me as usual,” he thought.  “Why not reverse operations and find out where they belong?”

It seemed hopeless:  as in a checker game they had him at disadvantage with the odd number of the “move.”  Theirs was the chance to observe, and an open attempt to follow them would be ridiculous.  Then, the footprints gave him an idea.

Dimly behind could be discerned the two men, as he quickened his pace, turning into a side street, off Fifth Avenue.  Here he knew that traffic would be light, and his footprints the best evidence of his progress.  The men unwittingly caught his plan, and dropped almost out of sight.  At the intersection of Madison Avenue, they quickened their steps, and caught up with him again.  Across corners, down quiet streets, and by purposed diagonals he led them:  still they dogged his footprints.  So adroit were they that only one experienced in the art could have realized their watchfulness.

Shirley now turned a corner quickly, into an unusually deserted thoroughfare, running with short steps, so as not to betray his speed by the tracks.  Before they had time to round the corner he ran up the thinly blanketed steps of a private residence.  Then he backed, as swiftly down the stoop, and thus crablike, walked across the street, down a dozen houses and backward still, up the steps of another private dwelling.  Inside the vestibule he hid himself.  The entry had strong wooden outside doors, and he tried the strength of the hinges:  they satisfied him.  A dim light burned behind the glass of the inner portal.  He quietly clambered up the door, and balanced himself on the wood which gallantly stood the strain.  Fortunately it did not come within four feet of the high ceiling of the old fashioned house.

He suffered a good ten minutes’ wait before his ruse was rewarded.  Being on the “fence” was a pastime compared to this precarious test of his muscles.  The two men who had followed the first footprints tired of waiting before the house.  One of them determined to investigate the other steps, which led into the house of their vigilance, from the other dwelling.  And so he followed on, to the vestibule where he rang the bell.  Shirley could have touched his head, so near he was, but the darkness of the upper space covered the retreat of the criminologist.