"That cross was made twenty years ago," he said. "In that time the storms could have destroyed all trace of it unless the Englishman carved it very deep, and in that event we should have discovered it already." "It must be found," persisted Canaris in his terror. "Hark! The firing is coming nearer. In half an hour the valley will swarm with savage foes. Go! Go! Go!" He fairly shrieked out the last words, and threw himself in despair down amid the jungle grass. The Greek did not exaggerate the danger. A startling confirmation of his fears was at hand. Warned in time by a commotion in the bushes, Guy and Melton dropped flat, as a savage, spear in hand, and bleeding from a wound in the head, burst out of the jungle twenty yards distant and made full speed for a rock a few yards to the north of that by which the Englishmen lay concealed. All unconscious of the three pairs of eyes watching his movements, he stooped, flung the tangled grass madly aside, and, rolling a loose stone from the base of the rock, revealed a dark cavity in the smooth side. He threw a frightened glance in the direction he had come, and, dropping his spear and diving into the hole, pulled the stone back in place from within. All this happened in less time than it takes to tell. "Saved!" burst thankfully from Guy's lips as he sprang to his feet. "Saved!" echoed Melton and Canaris. Snatching up their baggage, they dashed across the narrow space that divided the two great boulders. Guy tore the rock from the entrance, and, as the imprisoned savage within uttered a hoarse cry, he pointed his rifle at the opening. "Go ahead," called out Melton; "he's unarmed; he can't harm you." Guy hesitated for an instant, and then crawled into the forbidding cavern on hands and knees. A distant sound of scuffling and rattling of stones told that the savage was retreating into the bowels of the earth. Melton handed in the rifles and the baggage, and crawled in after them. Canaris was the last to enter, and with Melton's aid the stone, which was round in shape, was pulled back against the entrance, and all was darkness, save for one crevice an inch or two wide. The Greek peered sharply through this, and then exclaimed in a low whisper: "We are just in time. A party of Abyssinians are approaching through the jungle in pursuit of the Galla fugitive. "Hush!" he added; "don't make a sound; they are coming directly toward the rock." CHAPTER XVIII. THE UNDERGROUND RIVER. A moment of terrible suspense followed the Greek's announcement. From without could be plainly heard a chorus of angry shouts as the Abyssinians searched for their missing prey. Then the sounds grew fainter and Canaris said quietly: "They have gone on past the rock. We had better strike a light and see what has become of that black rascal. I cannot understand how he knew anything about this place. It may not be the proper entrance after all."