Back in his own cell again he lay down to sleep, for he had denied himself sleep a great deal of late that he might prosecute the work upon which he had been engaged. When he awoke the snakes were with him again and his friend was tapping gently on his chest, and once again he took up the dull monotony of his existence, altered only by regular excursions into his new found domain, the black interior of which he came to know as well as he did his own cell, so that he walked briskly from the hole he had made to the wooden column at the far end of the tunnel, passed around it and walked back again at a brisk gait and with as much assurance as though he could see plainly, for he had counted the paces from one end to the other so many times that he knew to an instant when he had covered the distance from one extremity to the other. He ate; he slept; he exercised; he played with his slimy, reptilian companion; and he paced the narrow tunnel of his discovery. And often when he passed around the wooden column at its far end, he speculated upon the real purpose of it. Once he went to sleep in his own cell thinking about it, and when he awoke to the gentle tapping of the snake’s snout upon his breast he sat up so suddenly that the reptile fell hissing to the flagging, for clear and sharp upon the threshold of his awakening mind stood an idea—a wonderful idea—why had he not thought of it before? Excitedly he hastened to the opening leading into the tunnel. Snakes were passing through it, but he fought for precedence with the reptilian horde and tumbled through head first upon a bed of hissing snakes. Scrambling to his feet he almost ran the length of the corridor until his outstretched hands came in contact with the rough bole of the tree. There he stood quite some time, trembling like a leaf, and then, encircling the column with his arms and legs, he started to climb slowly and deliberately aloft. This was the idea that had seized him in its compelling grip upon his awakening. Upward through the darkness he went, and pausing now and then to grope about with his hands, he found that the tree trunk ran up the center of a narrow, circular shaft. He climbed slowly upward and at a distance of about thirty feet above the floor of the tunnel, his head struck stone. Feeling upward with one hand he discovered that the tree was set in mortar in the ceiling above him.