The elder detective either did not notice the curious note in the younger one's voice, or noticing it, chose to ignore it, for with no change of manner he proceeded to say:
"I wish you would exercise your wits, Sweetwater, on the following troublesome question: if the arrow which slew this young girl was in one gallery at ten o'clock, how did it get into the other at twelve? The bow"—here he purposely hesitated—"might have been brought up the iron staircase. But the arrow——"
His eyes were on Sweetwater (a direct glance was a rare thing with Mr. Gryce), and he waited—waited patiently for the word which did not come; then he remarked dryly:
"We are both dull; you are tired with your day's work and I with mine: we will let difficult questions rest until our brains are clearer. But"—here he reached for the strip of dingy cloth he had cast aside, and tossing it over to Sweetwater, added with some suggestion of humor,—"if you want a subject to dream upon to-night, there it is. If you have no desire to dream, and want work for to-morrow, make an effort to discover from whose clothing that fell and what was its use. It was picked up in Room B on the second floor, the one where Mrs. Taylor was detained before going downstairs."
"Ah, something tangible at last!"
"I don't know about that; I honestly don't know. But we cannot afford to let anything go by us. Little things like that have not infrequently opened up a fresh trail which otherwise might have been missed."
Sweetwater nodded, and laying the little strip along his palm, examined it closely. It was made of silk, doubled, and stitched together except at the ends. These were loose, but rough with bits of severed thread, as if the thing had been hastily cut from some article of clothing to which it had been attached by some half-dozen very clumsy stitches.
"I think I understand you, Mr. Gryce," observed Sweetwater, rising slowly to his feet. "But a dream may help me out; we will see."
"I shall not leave here till ten to-morrow morning."
"Very good, sir. If you don't mind, I'll take this with me."