In vain the former heaved and hauled. He could hear Uncle Brian plaintively inquiring when he would be able to crawl through. "There's no help for it," decided Peter. "I'll have to go in again and clear the lash-up." He did not relish the task, but it had to be done. The journey through had been bad enough, but now, although the distance was much shorter, he was additionally hampered by the fact that he was working in utter darkness and that the baggage, filling the height and breadth of the tunnel, considerably interfered with the air supply. Peter realized the possibility of having to cast off the rope and remove each bundle separately--a task entailing at least half a dozen trips into the shaft. Fortunately this was spared him; for on feeling cautiously, he discovered the cause of the "block". The rifle had come unhitched and, swinging round until the muzzle caught the projecting rock, had jammed the whole contraption. It was a fairly simple matter to release the rifle and drag it into the open. Then the rest of the gear was hauled out with comparative ease. "All clear," shouted Peter again. Brian Strong made the passage quickly and easily. As a mining engineer, he was used to crawling through narrow passages. Had it been a case of making their way aloft to the fire-control platform of a battleship in a heavy sea-way, Peter would have won easily; but as a tunnel crawler, he admitted unhesitatingly that he did not shine. For the next mile, it was fairly easy going. The floor of the ravine was wider, but the height of the walls correspondingly higher. Here and there were pieces of rock that had become dislodged and had fallen, half buried in the sand. Once a stone as big as a man's head came hurtling down within twenty paces of them. The end of the chasm was now in sight, but they were not yet out of danger or difficulty. At about four hundred yards from the end their progress was arrested by a single slab of rock about ten feet in height that completely obstructed the passage. This time there was no tunnel. The only way was to climb over. "I'll give you a leg up, Uncle," suggested Peter. "Then I'll send up the gear and swarm up by the rope." He took up his stand close to the rock and was about to bend down to enable Uncle Brian to clamber on his back, when his boot came in contact with something hard, buried a few inches under the sand. As he trod on it, it gave with a rasping sound. "Hello!" he exclaimed. "What's this?" With the toe of his boot, he pushed aside the covering layer of sand, revealing a rusty breast-plate. Grasping the metal, he pulled it up. It came quite easily, disclosing a number of human bones lying on the backpiece of a suit of mail. A short distance away was a steel morion, together with fragments of a skull. The discovery roused Peter's interest far more than had the sight of the diamond-studded sand. "We're not the first people to find the gorge," he remarked. "How old is this, do you think, Uncle?"