gone, now," she said. "You may look over the plumbing in the bathroom whenever you are ready."
With a nod Duvall picked up his tools and followed her to the front of the apartment. As they left the kitchen, Mrs. Morton closed the door leading from it to the hall.
"I want you to stay here for the next hour, Sarah," she said, as she left the kitchen. "If anyone rings, I will answer the bell." A moment later she and Duvall were in the library.
The latter pretended to be busy inspecting the connections of the hot water radiator.
"Have you received any more threats?" he asked, in a low voice, without turning his head.
Mrs. Morton took the telegram that Ruth had received a short time before, and placed it in his hand.
"This came half an hour ago," she said, without further comment.
Duvall read it, then thrust it into his pocket.
"Did your daughter see it?" he asked.
"Yes. It had been delivered to her before I could prevent it."
"That is too bad. Was she much upset?"
"Yes. The thing is beginning to get on her nerves."
Duvall rose, and placed his tools in the kit.
"Please take me to your daughter's bedroom," he said. Mrs. Morton led the way.
The room was a fairly large one, situated in an ell at the rear of the building. Of its two windows, one, as has already been pointed out, overlooked the court between the apartment building and the house next door. The other faced toward the rear. Duvall placed his kit of tools upon the floor, and began an examination of the room. After a quick glance about, he turned to Mrs. Morton.
"Where was the letter found—the one that did not come through the mails?"
"Here." Mrs. Morton indicated a spot on the floor near the small enameled dressing table that stood against the east wall of the room. Its position was midway between the two windows. It was clear that whoever had entered the room might have done so through either of the windows; at least, the position in which the dressing table stood afforded no indication as to which one it might have been.
"Which of the two windows was open, when you found the letter?" Duvall asked.
Mrs. Morton indicated the one facing the court.
"This one," she said. "Not wide open. Perhaps six or eight inches."
"The other was not fastened, I suppose?"
"No. Ruth always keeps it raised during the night, but usually closes it while dressing."
Duvall went to the window, and opened it. It was well balanced and moved easily.
"Anyone coming up by way of the fire escape could, of course, have raised the window from the outside, and closed it again after leaving the room," he said, more to himself than to Mrs. Morton. Then he got out on the fire escape and made a careful examination of its surface.
"When was this ironwork painted?" he asked Mrs. Morton, through the window.
"About ten days ago."
"H—m." Duvall examined the newly painted iron surface with rather a blank expression. That anyone had walked upon it since it had received its newly applied coat was, he felt, out of the question. The paint was so new, so shiny, so yielding in its fresh glossiness that, even treading as lightly as he could, the marks of his shoes were plainly visible. He leaned over and pressed the palm of his hand upon the grated iron floor. The pressure of his hand was sufficient to dull the freshly painted surface. It seemed impossible that anyone, even in bare or stockinged feet, could have been upon the fire escape, without having left tell-tale marks upon it. He re-entered the room, and turned his attention to the other window.
Here the opportunities for entrance seemed even more unfavorable. The window was situated on the fourth floor. There was still another floor above, with a window similarly located. Anyone might, of course, have been lowered from this window above, to the sill of the one at which he now stood, and entered the room in that way. He examined with care the white woodwork of the window sill, also freshly painted. It showed no marks. This, of course, was not conclusive. He determined to investigate the occupants of the apartment on the top floor.
The wall of the brownstone dwelling house next door, which formed the east side of the narrow court, was of brick, covered with ivy. There were no windows in it whatever. Apparently it had once adjoined the wall of a similar house, where the apartment building now stood, and when the second house had been torn down to make way for the new building, the partition wall had remained as originally built, without windows.
Duvall examined this house next door with a great deal of interest. It was four stories high, with an attic, and rose to almost the same height as the fifth floor of the apartment house, owing, no doubt, to its ceilings being somewhat higher. In the sloping roof of the attic were three small dormer windows, facing the court, but the nearest one was perhaps twenty feet from the window of Ruth's room, in a horizontal direction, and some eight or ten feet above it. There was no way in which anyone could have passed from the attic window to that of Ruth's room, even supposing such a person to be an expert climber. Anyone lowered from this window by means of a rope would merely have found himself hanging against a bare brick wall, twenty feet from the window of the girl's room. Duvall, accompanied by Mrs. Morton, made his way back to the library.
"You feel quite certain about the cook?" he asked.
"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
