For the first ten feet or so, the going was rendered rather difficult by projecting bits of rock that caught at his clothes and impeded his progress. But then the passage widened out steadily until he could not feel the sides even when his arms were stretched to their utmost limit. The light that had followed him from the small entrance finally vanished, and he went forward with the utmost caution, carefully planting each foot for the next step. At any moment, for all he knew, he might find himself on the brink of a precipice. "Black as Egypt in here," he muttered to himself, as he felt for the matches he carried in an oilskin bag in the pocket of his coat. "I guess I'd better strike a----" But he never finished the sentence. A deafening roar resounded through the cavern and he was thrown violently forward on his hands and knees. Again came that dizzy, sickening shaking of the earth, that nauseating sense of being lifted to a height and suddenly let fall, that squirming of the ground beneath him as though it were a gigantic reptile. His earlier experience in the open air had been bad enough, but there at least he had had the sense of space and sunlight and companionship. Here in the darkness and confinement the horrors of the earthquake were multiplied. For more than a minute, which seemed to him an hour, the convulsions of the earth continued. Then they gradually subsided, though it was some minutes later before the quivering finally ceased. Dazed and bewildered, Allen Drew scrambled to his feet. His hands were scraped and bleeding, though he thought little of this in his mental perturbation. His thought turned instantly to Ruth. What might have happened to her while he was away from her? The trees were thick near the mouth of the cave. Suppose one had fallen and caught her before she could escape? He started to rush back to the entrance, but to his astonishment, could see no trace of the light that had marked the place where the opening had been. He stopped short, puzzled and alarmed. "That's queer," he muttered. "I guess that jar I got has turned me around. It must be in the other direction." He hastily retraced his steps. But as the cave grew wider and he found no sign of the narrow passage by which he had entered, he knew that he was wrong. "Must have had it right the first time," he thought, "but it's strange that I didn't see any light. Perhaps there was a bend in the passage that I hadn't noticed." Again he went back, feeling his way. The path narrowed and his outstretched hand came in contact with a shred of cloth that had been torn from his coat when he had entered. This was proof positive that he was on the right track. But where then was the light? The answer came to him with startling suddenness when he plunged violently into a mass of earth and rock that barred his way. _The entrance to the cave had vanished!_