He emerged into the fresh air and daylight, coughing incessantly. He called to make sure that Danville was following, but there was no answer. Astonished and concerned, he re-approached the entrance, calling. Not hearing any answer he was seized with panic fear. To reënter the cave was quite impossible. Even the outer entrance under the tree root was smoky, and the passage between the rocks was filled with the dense fumes. That was at about the moment when Danville thought to soak his scarf in the muddy water. Skinny shouted into the volume of emerging smoke, but it stifled him, even where he stood in the open, and he was compelled to withdraw from the entrance. It was then he had his inspiration. He remembered that very early that summer he and Charlie Avery, a new boy from Long Island, had seen a little speck of light in the low roof of the cave. Charlie had poked his scout staff up through this and Skinny had gone out and scrambled up to see if it had penetrated through to the open air. He found that it had, and that by reason of a rather odd condition. This cave was part of a jumble of dense brush and fallen trees; it had probably been made in some terrific storm. A tree on the hillock above the cave had been blown over, doubtless from the same cause which had uprooted the one below that formed part of the intricate entrance. Indeed the spot was a tangled jungle of rock and dense brush and fallen trees, and the cave only a grotto caused by the upheaval. In falling, this tree above the cave had wrenched part of its root up and it was just in this depression, now soggy and overgrown, that Charlie Avery's staff had gone through. If the little dungeon underneath had been lighted one could have seen the disturbance caused by that wrenching from above, and it was one of the standard jokes of Temple Camp to tell a new boy there were snakes in the cave and then direct his groping progress against a dangling end of root that hung down into the dank, earthy vault. The startled visitor usually reacted very satisfactorily to this. Here, you will understand, the roof of the cave was thinnest, and the ground in the excavation where the root had been was soft because of the water that was continually collecting in it and seeping through into the cave. Some day there would be a cave-in here, but no one ever worried about it. Skinny knew about all this and now it occurred to him that he might work open a hole in this soft depression and release the fumes more rapidly than they would escape through the entrance. It was, indeed, the only rescue work that he could do. He was already fearful that it would be too late to save his friend. If his effort resulted in a cave-in, even so that would release the smoke and probably not completely engulf the victim.