“This frail shaft may not look as if it would penetrate the human breast; but target arrows will drive entirely through a deer at eighty yards. . . . Why, then, the missing hunting arrow from the panel? An interestin’ point.”

Markham frowned and compressed his lips; and I realized that he had been clinging to the forlorn hope that the tragedy might have been an accident. He tossed the arrow hopelessly on a chair, and walked toward the outer door.

“Let’s take a look at the body and the lie of the land,” he said gruffly.

As we emerged into the warm spring sunlight a sense of isolation came over me. The narrow paved areaway in which we stood seemed like a canyon between steep stone walls. It was four or five feet below the street level, which was reached by a short flight of steps leading to the gate in the wall. The blank, windowless rear wall of the apartment house opposite extended upwards for 150 feet; and the Dillard house itself, though only four stories high, was the equivalent of six stories gauged by the architectural measurements of to-day. Though we were standing out of doors in the heart of New York, no one could see us except from the few side windows of the Dillard house and from a single bay window of the house on 76th Street, whose rear yard adjoined that of the Dillard grounds.

This other house, we were soon to learn, was owned by a Mrs. Drukker; and it was destined to play a vital and tragic part in the solution of Robin’s murder. Several tall willow trees acted as a mask to its rear windows; and only the bay window at the side of the house had an unobstructed view of that part of the areaway in which we stood.

I noticed that Vance had his eye on this bay window, and as he studied it I saw a flicker of interest cross his face. It was not until much later that afternoon that I was able to guess what had caught and held his attention.

The archery range extended from the wall of the Dillard lot on 75th Street all the way to a similar street wall of the Drukker lot on 76th Street, where a butt of hay bales had been erected on a shallow bed of sand. The distance between the two walls was 200 feet, which, as I learned later, made possible a sixty-yard range, thus permitting target practice for all the standard archery events, with the one exception of the York Round for men.

The Dillard lot was 135 feet deep, the depth of the Drukker lot therefore being sixty-five feet. A section of the tall ironwork fence that separated the two rear yards had been removed where it had once transected the space now used for the archery range. At the further end of the range, backing against the western line of the Drukker property, was another tall apartment house occupying the corner of 76th Street and Riverside Drive. Between these two gigantic buildings ran a narrow alleyway, the range end of which was closed with a high board fence in which had been set a small door with a lock.

For purposes of clarity I am incorporating in this record a diagram of the entire scene; for the arrangement of the various topographical and architectural details had a very important bearing on the solution of the crime. I would call attention particularly to the following points:—first, to the little second-story balcony at the rear of the Dillard house, which projects slightly over the archery range; secondly, to the bay window (on the second floor) of the Drukker house, whose southern angle has a view of the entire archery range toward 75th Street; and thirdly, to the alleyway between the two apartment houses, which leads from Riverside Drive into the Dillard rear yard.