One night, as Larry was returning from the school, and going up the stairs that led to his home, he saw, standing in the hallway, beneath the gas jet that illuminated it, a short man, rather roughly dressed. The stranger started on seeing the boy, and went quickly into a room the door of which someone on the inside opened. “I wonder what that means,” Larry thought. “That apartment was vacant yesterday. I wonder if it’s been rented. If it has I don’t like the looks of the tenants. However, it’s on the floor below us, so I don’t suppose it makes much difference.” Larry asked his mother, before going to bed that night, if she knew anything about the people in the rooms below. “I did not know they had been rented,” said Mrs. Dexter. “Maybe they are sneak thieves,” said Larry. There had been a number of cases of late of men sneaking into tenement houses, and, while the people were temporarily away from their apartments, ransacking the places. “I think I’ll speak to the janitor about it,” said Larry. “He’ll know if they have rented the rooms or not.” The janitor lived in rooms in the basement, and Larry, after cautioning his mother to keep her door locked, went downstairs. “Yes, I rented the rooms to three men, late this afternoon,” the janitor told Larry. “They said they were bachelors and didn’t have much furniture. I didn’t like the looks of the fellows, but I couldn’t say anything, as they paid cash in advance.” “Did they move their stuff in?” asked Larry. “Not that I saw,” replied the janitor. “If they did they must have brought it in hand satchels, for there have been no trucks bringing any furniture.” “Some of them are in the rooms now,” Larry went on. “They are, eh!” spoke the janitor. “I don’t like that, but I s’pose they’ve got a right to go in and out when they please, even if they haven’t any furniture. Maybe they’re looking the rooms over. It looks suspicious. I guess they’ll bear watching.” “I think so myself,” replied Larry, as he went back upstairs. CHAPTER XXI LARRY ON THE WATCH As he passed the door of the room which he had seen the stranger enter Larry paused. He saw a light under the portal where there was a crack between the sill and the edge of the door. He also heard voices in low conversation. “I’d like to know what you’re up to,” thought the boy. “I’ll bet it’s no good, from the looks of that one chap.” Larry noticed that the room occupied by the men was directly under his own bedroom. “Maybe I can hear something from my room,” Larry thought. He returned to his mother’s apartments to tell her what the janitor had said. He did not mention his own suspicions, for he did not want to cause any unnecessary alarm. When the others had retired that night Larry got out of bed, lay down on the floor of his room, and pressed his ear to the boards. At first he could distinguish nothing.