Thrusting his head and shoulders into the gloomy recess, Little Snap shouted at the top of his voice to the missing men, but only the hollow echoes of his cries, which seemed to reverberate from a long distance away, answered him. "Thet ain't enny use, fer I hev hollered till I'm hoarse," declared Mrs. Raggles, the tears coursing down her thin cheeks, while she wrung her hands in the abandon of her grief. "Durst ye go in there, mister?" "Yes; I am going," replied the postboy, preparing to enter the mysterious place. "Do be careful," implored Mrs. Raggles. "You won't be gone long, will you?" "I will be back in a few minutes—if I come at all. I shall——" Little Snap's speech ended with a startling exclamation. CHAPTER IV. WHAT LITTLE SNAP SAW. Before entering the unknown dangers of the mysterious cave, Little Snap had seen that Jack was standing a short distance away, as complacently as might be. "If I do not come back, Jack, go on to Daring's Diamond with the mail," he said, speaking as if to a human being. The intelligent animal pricked up his ears, and answered with a low whinny. The postboy's body was inside the mouth of the cavern when he had begun the speech to Mrs. Raggles. It was too dark for him to see more than that the underground pathway descended at an angle of about forty-five degrees. But the moment his feet touched upon this portion of the rock he suddenly found himself slipping down the decline at a rapid rate. In vain he threw out his hands to stop himself. The surface was like glass, over which he shot with the rapidity of lightning. He may have uttered a cry at the outset, but the shock was so sudden and thrilling that he was unconscious of it if he did so. His whole attention was centered upon trying to check his fearful momentum. He was carried onward near to the right wall, and he succeeded in catching upon the rough surface twice during his wild passage. The first time his hands slipped upon the wet, slimy rock, the mishap seemed to give greater impetus to his descent. Profiting by this failure, he seized upon another projection with a firmer hold, but the rocky knob broke away beneath his weight, and the piece went flying from his bleeding fingers ahead of him on the downward course. Its collision with the glassy floor caused a dull reverberation to go through the subterranean recesses, quickly followed by a sharp splash of water! This last sound came from below him, and Little Snap had barely time to understand that an abyss of great depth yawned at his feet before he was upon its very brink. The warning from the stone came barely in season for him to renew his efforts to catch on the rugged wall, which he did with more vigor than before. Again he found his hold broken, by the fearful momentum with which he was carried on, but the shock was such that he was lifted up clear from the rock and carried completely over the chasm.