The other had also caught a faint rustling sound, and knew that in all probability the two captains must be about to join them. Surely enough, in a short time the men reached the side of the boys, exercising all the skill possible to avoid making their presence known to others. Few words passed between them, for the plan of campaign had been laid out, and each one knew what lay before them. The firelight flickered upon the side of the supply tent, and it was in this quarter mostly that their gaze was fastened. In fact, Captain Lewis and his fellow officer depended wholly on the wide-awake boys to let them know when anything happened, for they themselves lay stretched out at full length upon the ground. One by one the men sitting by the fire began to vanish, some yawning, and others simply stretching themselves with the air of weariness natural after a strenuous day at the oars. Finally an atmosphere of desertion seemed to have come upon the camp. The fire died down slowly, and not a movement could be seen. Somewhere, near by, the appointed sentries stood guard, but their duty was wholly in the line of making sure that an enemy did not surprise the adventurous company from without. Those in the camp were supposed to be above suspicion. Roger was beginning to grow impatient. The minutes were dragging along, so far as he was concerned, and he began to fear that, after all, the scheme, so cleverly planned by Captain Lewis, would fail to be a success. What if the fellow had become suspicious, and determined not to allow himself to be attracted by the bait? They would have their long night vigil for nothing, and be no nearer to learning the truth than before. Roger lacked the patience and perseverance of his chum, though he had many good qualities of his own. It must have been almost midnight when Dick caught sight of a shadowy figure moving just beyond the supply tent. At first he thought it might be a wolf that had boldly crept into the camp, though such a thing seemed absurd; then he became satisfied that it must be a man on his hands and knees, crawling along slowly, and heading for the isolated tent. When satisfied in this respect he whispered in the ear of Roger, and touched both the recumbent captains on the arm. This had been a signal agreed on in case of necessity, and, as they were on the alert, they lost no time in making good use of their eyes. The creeper was now close to the tent. Every few feet he would sink down flat to the ground, and remain perfectly still for a time. No doubt at such intervals the man was listening intently to discover the slightest movement in the camp that might mean danger to him. Both boys fairly held their breath when they saw the shadowy figure reach the tent and hastily creep under the flap. Just how long it would take him to find what he was after no one could say, but the time had arrived for those who were watching the tent to make a forward move.