After a time he became aware that he was sitting in an atmosphere growing dense with smoke. The air current had become reversed, at intervals, and had sent the smoke pouring out from among the charred timbers in dense volumes. It choked the boy, and he was obliged to move. Instinctively he made his way along the passage to which he was most accustomed toward the foot of the plane. Here he stopped and seated himself again, but he did not stay long. The smoke soon reached him, surrounded him, and choked him again. He walked slowly up the plane. When he reached the head he was tired and his limbs were trembling. He went across to the bench by the wheel and sat down on it. He thought to wait here until help should come. He felt sure that he would be rescued; miners never did these things by halves, and he knew that, sooner or later, he should leave the mine alive. The most that he dreaded now was the waiting, the loneliness, the darkness, the hunger perhaps, the suffering it might be, from smoke and foul air. In the darkness back of him he heard a noise. It sounded like heavy irregular stepping. He was startled at first, but it soon occurred to him that the sounds were made by the mule which he had left there untied. He was right. In another moment Jasper appeared with his head stretched forward, sniffing the air curiously, and looking in a frightened way at Ralph. "Hello, Jasper!" The boy spoke cheerily, because he was relieved from sudden fright, and because he was glad to see in the mine a living being whom he knew, even though it was only a mule. The beast came forward and pushed his nose against Ralph's breast as if seeking sympathy, and the boy put up his hand and rubbed the animal's face. "We're shut in, Jasper," he said, "the breaker's burned, an' things afire have tumbled down the shaft an' we can't get out till they clean it up an' come for us." The mule raised his head and looked around him, then he rested his nose against Ralph's shoulder again. "We'll stay together, won't we, old fellow? We'll keep each other company till they come for us. I'm glad I found you, Jasper; I'm very glad." He patted the beast's neck affectionately; then he removed the bridle from his head, unbuckled the harness and slipped it down to the ground, and tried to get the collar off; but it would not come. He turned it and twisted it and pulled it, but he could not get it over the animal's ears. He gave up trying at last, and after laying the remainder of the harness up against the wheel-frame, he sat down on the bench again. Except the occasional quick stamping of Jasper's feet, there was no sound, and Ralph sat for a long time immersed in thought.