"That's the word. I remember because I asked him if he didn't mean 'rattled,' and he said, 'No, wabbled, sort o' dull-like.'"
"At any rate, that clears up one angle of the case. The box was not empty when it was delivered! Granting that the Filipino was telling the truth, it was not empty when he placed it on the table in this room! That means that it was not empty when Marshall Montgomery, after locking and bolting his door, took off the wrapping paper and lifted the lid! You've searched the room thoroughly, of course?"
"Every inch of it. We didn't leave a—"
But the chief suddenly halted, his sentence unfinished. To the ears of both men there had come a sound, faint but distinct. The sound of the rattling of paper somewhere in the room.
Involuntarily Preston whirled and scrutinized the corner from which the sound appeared to have come. The chief's hand had slipped to his hip pocket, but after a moment of silence he withdrew it and a slightly shamefaced look spread over his face.
"Sounded like a ghost, didn't it?" he asked.
"Ghosts don't rattle papers," snapped Preston. "At least self-respecting ones don't, and the other kind haven't any right to run around loose. So suppose we try to trap this one."
"Trap it? How?"
"Like you'd trap a mouse—only with a different kind of bait. Is there any milk in the house?"
"Possibly—I don't know."