“I grant the hammer is less easily identifiable. But I’ve hunted for fingerprints on the hammers and mallets around the premises, and there are no prints on them except the ones legitimately there. This isn’t proof positive, but it’s fairly so, when you take it in connection with the absence of any such nails as we’re searching for, and the unlikelihood of any of the under servants being able to get access to Mr. Tracy’s apartments. Except for Griscom, none of them is allowed in the living rooms at night, and I don’t suspect Griscom—yet.”

“Now Ames and the two secretaries were inside the house, but Mrs. Dallas was not,” Moore prompted further disclosures.

“Well, like Miss Remsen, Mrs. Dallas’s having a latchkey puts her on an even footing with the people in the house. And I can tell you, anybody with a latchkey could get into that house unheard. I’ve tried it, and the door latch and lock are so slick and so well oiled that they move with absolute silence. Then the thick, soft rugs in the hall and on the stairs are soundproof, and there’s no creaking step anywhere. Of course, all the appointments of that house are perfect, but it’s especially true of the precautions taken to eliminate noise.”

“Purposely so?”

“I daresay. It may be old Tracy had a special objection to noise and so guarded against it. But that doesn’t matter; the fact remains, anybody could go all over that house without making a sound, if careful enough.”

“Then, whether the murderer was a member of the household, or a silent intruder from outside, how did he get away from Mr. Tracy’s suite of rooms, leaving the outer door of the suite locked behind him?”

March looked Keeley Moore squarely in the face.

“Have you no idea?” he said.

“Have you?” countered Moore.

“Oh, yes, I have. He went out the window.”