The janitress permitted Nick to see the rooms which Madame Ree had vacated, but there was nothing to denote that she had ever occupied them. In a brown study, Nick left the place and walked from Chestnut Street to Market. Presently his eye brightened and his lips tightened. Ideas, at first confused, were taking definite shape. There was a riddle to solve, and his acute brain had evolved what might prove to be a start toward the solution. With a determined mien, he ascended the elevator of the factory building and was soon before the door of the office. The corridor was clear, there was no one about. With his picklock he opened the door, passed in, shut the door, and then proceeded to take a close survey of the office. Between the two front windows was a large roller-top desk. Against one of the narrow sides of the room was the safe. Opposite, against the other narrow side, was a small desk, used by Dashwood. By the side of the safe was a door opening into the president's private apartment. It was partly open, and Nick went in. Nothing there except a desk, a closet, and a few chairs. After a thorough inspection, the detective returned to the main office. Here the clean floor and the absence of dust denoted that the janitor had performed his usual work that morning. There was a waste-basket for each desk. The one by the small desk was empty; the other, by the large desk, contained a few torn scraps of paper. Nick took them up one by one, saw that they were all from envelopes and printed circulars and catchpenny advertisements, and threw them back into the basket. The great detective now took a position near the door and fronting the large desk, and tried to put himself in the place of Gabriel Leonard, at the time of his visit to the office the night before, a visit which had resulted in the discovery of Filbon's dishonesty. "He came up for an important purpose," ran the detective's thought, "for he sticks so close at home evenings that nothing short of important business could have called him out. Was it a suspicion of Filbon's crookedness? Or was it a purely personal matter having no relation to the books of the company? Impossible, at this moment, to say, unless--unless the remarks of Madame Ree, overheard by the saloon man down-stairs, had reference to Gabriel Leonard. She said: 'It's risky, but it has got to be done, for that old fool may after all fail to come.' "She then started for the elevator to do that which she had declared had got to be done. "What was that?