"What does it mean?" I asked, although I could guess.
"The dark spots are blood, the discoloration the poison from the needle."
"And the needle?"
He shrugged his shoulders. "That's where our very scientific culprit has forestalled me, Walter! The needle was in these curtains all day yesterday. Unfortunately, I did not study the manuscript, did not attach any importance to Miss Lamar's scene at the portieres."
"The man who broke in last night—"
"Removed the needle, but"—almost amused—"not the traces of it. You see, Walter, after all, the scientific detective cannot be forestalled even by the most scientific criminal. There is nothing in the world which does not leave its unmistakable mark behind, provided you can read it. The hole in the cloth serves me quite as well as the needle itself."
Very suddenly a voice from behind us interrupted.
"Find something?"
I turned, startled, to see Emery Phelps. There was a distinct eagerness in the banker's expression.
"Yes!" Kennedy faced him, undisturbed, apparently not surprised. His scrutiny of Phelps's face was frank and searching. "Yes," he repeated, "bit by bit the guilty man is revealing himself to us."