He went on into his bedroom, thinking over the problem. He was recalled to earth very suddenly as, in his bare feet, he stepped on a loose tack. “Ouch!” the boy exclaimed in a whisper as he grabbed his wounded toe in his hand. “I forgot about the carpet being up. Hello! What’s that?” His attention was attracted from the pain of his foot to a streak of light on the floor of the room. It showed plainly, now that the carpet was up and the room in darkness, for Larry did not need a lamp to undress by. “That comes from the room below--the room where the strange men are,” thought Larry. “There must be a hole in the plaster of the ceiling right under where the hole in my floor is. That’s the reason the light shines through. I wonder if I can see down.” For an instant Larry hesitated. He did not like the idea of spying on people, but, in this case, he felt that he was justified. There was something suspicious about the men. The janitor had said they had brought no furniture, yet they were constantly in the place at night, and often during the day. True, their business might be legitimate and honest, but the indications were to the contrary, and Larry felt that he owed it to his mother and himself to see that there was no harm in what the men were doing. So the boy kneeled down on the bare floor, and put his eye to the crack. At first he could make out nothing, as the space between the boards in the floor of his room was so small that little of what was going on in the room down below showed. Larry soon fixed this, however, by softly cutting away a portion of the board. The hole in the plaster of the ceiling on the room below was big enough to disclose considerable. When he had the hole made larger, Larry again applied his eye. This time what he saw startled him. There, just below him, and seeming quite close, by reason of a bright light, were three men. One of them Larry recognized as the man he had so frequently seen, and the same one who had followed him that evening. All three were in their shirt sleeves and seemed to be working hard. They hurried back and forth, carrying something in small pots over to a long table. All the while came that curious roaring sound. Larry wiggled around until he had found a spot where he could get the best view of all that was going on in the apartment below. Suddenly there came the sound of a slight explosion. “Turn off the gas! It’s getting too hot!” Larry heard one of the men exclaim. He kept a close watch. He saw one of the men dart forward. Then the fellow came to a stop in front of a small gray object. He seemed to pull open a little door and, all at once, the room was flooded with a golden glow of a small gas furnace, the brick lining of which was at white heat. The men pulled something from the interior of the furnace with a long-handled affair like a rake. “Get ready to pour,” he heard one man say.