He unlocked a little drawer, and took out some photographs which he laid on the table.

“I have numbered them, 1, 2, 3. Will you describe them to me?”

I studied the proofs attentively.

“All greatly magnified, I see. No. 1, I should say, are a man’s finger-prints; thumb and first finger. No. 2 are a lady’s; they are much smaller, and quite different in every way. No. 3”—I paused for some time—“there seem to be a lot of confused finger-marks, but here, very distinctly, are No. 1’s.”

“Overlapping the others?”

“Yes.”

“You recognize them beyond fail?”

“Oh, yes; they are identical.”

Poirot nodded, and gently taking the photographs from me locked them up again.

“I suppose,” I said, “that as usual, you are not going to explain?”