They did not go very close to the old mill, but halted at the foot of the trees before mentioned. Andy boosted the others into a tree and then climbed up himself. Then the acrobatic youth led the way, from one tree to another. All moved closer to the mill without making any noise. There was no moon, but the stars were shining brightly, and by the light they saw the building loom up before them. Not a light was to be seen, and the only sound that reached their ears was the roaring of the Falls some distance away. “Now then, be careful!” whispered Andy, as he moved out on the end of a limb. “Don’t make a noise when you drop on the roof.” As he went out the limb bent beneath his weight until it rested on the shingles of the roof. He alighted on the top of the mill with ease, and one after another the others followed. [Illustration: The limb bent beneath his weight.] The roof was of the low, gabled sort, with several windows at either end of the building, just below the top. Andy crawled over the shingles with the ease of a trained athlete and looked over the edge. One of the windows was within three feet of him and he noted with satisfaction that one of the sashes was completely gone and the other was minus its panes of glass. “I’d hate to break any glass—it would make such a noise,” said he. “Now then, the rope.” This was quickly made fast and Andy went down and crawled through the window into the loft of the mill. The others came after him. Then the five boys stood in a circle, almost holding their breath, and wondering what they had best do next. “Well, we are in the place anyway,” murmured Pepper. “Yes, and they haven’t dropped us into the river either,” added Andy. It must be admitted that the hearts of the four cadets thumped wildly in their bosoms. They realized that they were in a dangerous situation, and there was no telling what would happen next. Bert Field was strangely self-possessed, even though his nerves were at a high tension. “I’ll go first,” said he. “I think it is my place to do so.” “Well, we’ll watch out, and do all we can to protect you, and ourselves, in case of trouble,” answered Jack. Having listened for several minutes, the boys grew bolder and Bert Field lit a small bullseye lantern he had brought along. By the aid of the light, they tiptoed their way across the loft floor and down a narrow pair of stairs. “Listen!” said Bert, suddenly, and came to a halt. He shut off the light, and all came to a halt and strained their ears. From a distance came a murmur of voices. Three men were talking in one of the rooms of the old mill. Then the boys saw a ray of light shining under a closed door. “They are in that room,” said Bert. “I’m going to the door and listen to what they have to say.” He moved on and so did the cadets, all anxious to listen to the conversation. Now the boys were certain they had only human beings to deal with they felt better.