What?
From garret to cellar, thirty rooms in all; nothing but the hand-print on the newel-post and the opened trunk.

Haggerty returned to the museum, turned out all the lights except that on the desk, and sat down on a rug so as not to disturb the dust on the chairs.

The man might return.

It was certain that he, Haggerty, would come back on the morrow.

He was anxious to compare the thumb-print with the one he had in his collection.
For what had the man come?
Keep-sakes?
Haggerty dearly wanted to believe that the intruder was the one man he desired in his net; but he refused to listen to the insidious whisperings; he must have proof, positive, absolute, incontestable.