But Sep, one of whose qualities was an absolutely unselfish power of self-sacrifice, prevented him. “Don’t be absurd, Rees,” he said quietly. “I can climb better than you, and it may come to be a climbing matter. Give me the lantern.” He took it from his companion’s unwilling hand, and began the descent. But when he had gone ten or twelve steps it seemed to Rees that the lantern swung from side to side, and that Sep was going down very slowly. “Are you all right, old man?” he asked anxiously. No answer. At that moment the light in the lantern went suddenly out, and there came up to his ears a dull sound like the fall of some heavy body. “Sep, Sep, are you all right?” again he shouted, in a voice that rang in the hollow space. Again no answer. The truth flashed upon him. The cavernous abyss below him was full of foul poisonous gases, such as he had often heard of at the bottom of old wells. There was not a moment to lose. Already poor Sep, stupefied by the noxious vapors, might be beyond the reach of help. Fastening the rope they had brought with them to the top of the perpendicular iron railing in such a manner that the knots, wedged in on the top step, kept it firm, he fastened the other end round his waist, and half-climbed, half-slid down into the blackness below. He had not gone down far, however, before he began to feel the influence of the vapors which had overcome his friend. He found himself growing giddy, and then for a moment, which seemed to him an hour, he partly lost consciousness of what he was doing. But he struggled with this creeping paralysis, and by a strong effort of will recovered command of himself and remembered his errand. The length of the rope just enabled him to get to the bottom of the steps. The darkness was absolute. He held his breath to avoid inhaling any more of the foul, heavy air than he could help, and, stooping down with outstretched hands, touched the insensible body of his friend. He gathered him up with the support of the rope, and being lucky enough to find the iron handrail at once, he dragged himself and Sep up the rugged steps as quickly as the heavy burden would permit. Rees’s movements had been so rapid that the whole proceeding of descent and ascent had not occupied more than a minute. Short as the time was, however, it had been long enough for the poisonous gas to take effect. By the time they got to the little chamber which contained the opening of the drain, Rees felt that he was succumbing to its influence, and that the only chance, not only for Sep, but for himself, lay in reaching the purer air above. He staggered across the muddy floor, and with efforts which grew every moment more frantic as again he felt a dizziness like approaching death come over him, he dragged his companion, whether dead or alive he did not know, up--up to the floor of the vaulted room. “Thank God! thank God!” he cried deliriously; and then he turned, thinking the voice was that of some one else.