This feat he accomplished, after considerable difficulty; then, while he stood essaying to leap, the brute beneath him swerved suddenly to the right. It might have been that the scientist’s movements irritated the creature, and so caused it to change its course, or it may have been but a whim on its part. However it was, the sudden move destroyed the professor’s balance; he was flung headlong and dropped, in a stunned and bleeding heap, beside the track. Nought he knew of the coming of the wolf-men who had already captured Garth; nought of the passage of the bridge; even the rough journey thence to the caves of the savages did not rouse him. When he did at length return to a sense of things around him, two impressions forced themselves upon his brain. One was the sensation that utter, impenetrable darkness shut him in--darkness, thick and tangible; the other, that every bone in his body had been broken and re-set. Of the twain, the former gave him the more uneasiness. His aches and pains, he knew, were the result of his fall, but this other he could not explain. Where was he, that this darkness surrounded him? Surely, if he lay where he had fallen, the twilight of the underworld would be about him? Then of a sudden the thought that he was blind swept over him. _The shock of his fall had perhaps destroyed his sight!_ “Oh, God!” he cried despairingly, and raised his hands. The clank of metal startled him, and he became conscious of something which, in his state of semi-bewilderment, he had not felt before. His arms were chained at the wrists! A low gasp escaped him at this discovery, yet with it came a feeling of relief. The darkness, then, was the result of his surroundings, and not of any accident to his eyes. But into whose hands had he fallen? What beings were they who held him captive? As yet he was unaware of the existence of the wolf-men, and it was well that he knew nothing of the horrors, or surely his brain would have given way beneath the strain of his terrible situation during the long hours he spent in the darkness of his prison. His first action was to attempt to slip the chain from his wrists, but this he found before long to be an utter impossibility. Evidently the creatures who had fastened him had a shrewd idea as to the method of securing a prisoner. Luckily, his feet were not in a like plight, so that, after a time, he made shift to rise, and, with manacled hands outstretched before him, feel his way about his prison. As nearly as he could judge, his cell was about four yards in length by rather less than half this in width. Its rock walls, rough-hewn and rugged for the most part, were, in one particular place, smooth as glass. Carefully Mervyn passed his fingers over this slab, suspecting that it was the door to his cell yet not a crack could he find. The rock there seemed not less solid than elsewhere. Again and again he tried, but never with the same result.