When, after a tedious journey along the murky margin of the lagoon, they finally reached the mouth of the subterranean stream, they found the entrance blocked by a mass of stones. Nor was the barrier the result of a landslide, as they had supposed when they tried to force their way through from the other side; the stones had been placed there by human hands. Some one had indeed anticipated their return and had tried to forestall them in every way. Then they returned to the cave in which the gold had been concealed and carefully looked around for traces or clews of the one who had removed the treasure, and after a lengthy search their efforts were rewarded. A faint trail led from the entrance toward the great wall. They followed the indistinct path, breathless with anticipation; it ran straight to the point where the wall joined the abrupt mountainside. And there, under the massive structure, a hole had been dug large enough for men to pass freely to and fro. The gold had been carried back into the Hidden Valley. “Quizquiz!” both shouted in one breath. “It was he. No one else would have thought of it or had the cunning to put through such an undertaking.” The hole had been partially blocked with a heap of earth and stones. “Not even this place, which had the reputation of being the home of the devils, could stop Quizquiz,” Stanley said. “I see through it now. After our escape in the canoe he planned to get us back. He had the hole dug and found that we were gone. Then they saw the underground river. Putting two and two together, he could easily figure out how we got away. He knew we should return, so he had the river blocked and carried away the gold.” “We are stumped, all right,” Ted admitted. “All my wonderful plans have gone soaring. We might as well go back and forget about the whole thing. But it is a bitter pill to swallow.” They made their way to the plane slowly and suffering all the agony of keenest disappointment; their hopes and ambitions were not to be realized. Their dreams of the future had vanished in thin air. “Let’s have a bite to eat,” Stanley suggested. “I feel faint and weak. Then we can fly back to the field, give up our jobs, and get back home--soon, I hope; the sooner the better.” “What about all the stuff we brought with us?” Ted asked. “We shall not need it.” “No! We might as well dump it. No use to carry back the extra weight. And, by the way, what is in those boxes? They are awfully heavy. I could tell we had a big load aboard because I could not get the ship to climb fast.” “That is the dynamite,” Ted said calmly. “What?” in consternation. “Dynamite. About a hundred pounds of it!” “Do you mean to tell me those boxes are full of dynamite?” “Certainly. We should have needed it to blow open the entrance to the underground river.” “Good heavens!” Stanley fairly shrieked. “Think of carting along a load of dynamite in a country like this. If we had had a forced landing we should have blown into bits.”