Just to the left of the connecting door, and in the general office, stood the desk occupied during business hours by Clay Fairchild. Above this desk was another incandescent light, which the Captain lighted, after which he took up whatever trail he had been following so closely, at the exact point where he had left it, continuing, in a stooping posture, to the hall door of the general office. From the point where he had picked up the hairpin, immediately within the entrance to Room 4, he had pursued a course away from the hall, through the connecting door to Room 5, and back again toward the hall to the hall entrance of the latter room,—the whole forming, roughly, an arc, the chord of which was the hall.
At the door of Room 5 he stood upright once more, and the young man became aware all at once that he was being eyed quizzically.
"Look!" the Captain whispered. Stooping again, he pointed to the heavy ply of the moquette carpet.
For a moment Lynden could descry nothing unusual; his heart was thumping in a manner for which he could assign no reason; but when the Captain traced an outline with his thumbnail, he could see quite distinctly the imprint of a small, partial footprint, such as a woman's French heel might make.
"That appears at just two other places," Converse continued; "at the entrance to Room 4, where I found the hairpin, and just inside this room; and there, beyond that desk, near the connecting door. They were made by a woman who stood a while at the first door, and who then, I believe,—though I can't be positive,—tiptoed to the connecting door, where she paused again for a while. She either tiptoed between those points, or stood for a time; the marks wouldn't have remained had she walked directly through the two rooms."
Lynden stared at the tiny impression—so faint that nobody else would ever have remarked it—and seemingly sought to frame a reply that he could voice naturally.
"Wonderful! Wonderful!" was all he said, but in tones so low that they were scarcely louder than Mr. Converse's whisper.
The latter now turned to the rest of the room. Swiftly, but apparently permitting not the least article to escape his observation, he made the circuit of the apartment, and finally paused at Clay Fairchild's desk. Almost instantly his eyes singled out one from among the mass of papers which littered it. This he carefully folded, and placed, with the article he had picked up on the stairway, which Lynden had been unable to see, in the capacious pocketbook. He seemed reluctant to leave this desk; after he had turned away he paused and cast another look at it, sniffing as one striving to locate the source of a faint odor. Lynden paused too; he glanced hurriedly from right to left, his brow lined, his expression troubled and perplexed.
At length they returned to Mr. Nettleton's private office, which was subjected to as close and thorough an examination as had been the room just quitted. Only one thing seemed especially to hold Converse's attention, and that was the space beneath the lawyer's desk. Here he got down to his hands and knees, and struck no less than five matches in an effort to obtain a better light. Whether the dusty space told him anything Lynden could not determine.
They passed back into the hall again. Converse walked directly to the entrance of Suite 2, immediately adjoining Doctor Westbrook's offices, on the side nearest the stairway. A small card pasted on the ground glass of this door bore the words "To Let." Converse ignited another match, in the added light of which he examined the door-knob. His companion observed him touch it with the tip of a finger, and shake his head, as if something incomprehensible had all at once presented itself.