"Sarah?" Mrs. Morton smiled. "What do you think? You've seen her." "She certainly appears to be above suspicion," Duvall replied. "But one can never be sure. Suppose you send her out on some errand. I should like to search her room." Mrs. Morton left him for a few moments, and presently the old colored woman passed down the hall and left the apartment. Then Duvall, accompanied by Mrs. Morton, made a thorough examination of the woman's room. His search disclosed nothing of interest, nor was a similar search of the room of Nora, the maid, productive of anything that could in any way connect her with the mysterious warnings. There remained only the occupants of the fifth floor apartment. Duvall requested Mrs. Morton to summon the janitor of the building, and explain to him, in a guarded way, that he wished to ask him certain questions. The janitor proved to be a good-natured fellow, who seemed extremely anxious to please Mrs. Morton in every possible way. In answer to a question from the latter, he said that the apartment on the top floor was vacant, and had been vacant for nearly two months. The family that had occupied it, he explained, had moved away, and had requested the management of the building to sublet it. This they had not yet succeeded in doing. "May I go up and look it over?" Duvall asked. "Sure you may," the janitor replied, and he and Duvall went to the elevator, leaving Mrs. Morton waiting in the library. The apartment on the top floor had been newly done over, and smelt of fresh varnish and paint. The shiny floors had scarcely been walked upon, since they had been refinished. The air was close and warm, by reason of the tightly closed windows. Duvall proceeded at once to the room directly over Ruth's bedroom. To his disappointment the two windows were not only closed and fastened, but so tightly stuck on account of the fresh paint that it required the combined efforts of the janitor and himself to open them. That they had been opened, since the painting had been done, some ten days before, was clearly out of the question. Duvall made up his mind at once that however the person who had placed the mysterious message in Ruth's room had effected his or her entrance, it had not been by way of the apartment on the top floor. Somewhat disappointed, he went to the floor below, and thanking the janitor for his kindness, rejoined Mrs. Morton. "What have you discovered, Mr. Duvall?" the latter asked, eagerly. "Nothing, so far. I confess the thing is somewhat of a puzzle." "Someone _must_ have been in Ruth's room." "Not necessarily." "But--why not?"