“That was fine!” praised Dr. Rander. “You never flinched. Now let’s hurry up the mountain to the treasure.”

“Do you suppose the mules will be safe over there?” queried Joe anxiously. “We couldn’t take any food with us across the river. If anything should happen to them——”

“There is no danger,” the old man assured him. “Probably no one has been in this section for years and years.”

Notwithstanding this, the young men were still worried. They realized that they would be in a grave predicament if anything should befall the provisions.

This anxiety gradually wore off, however, as they neared the treasure cave.

“Hard climb, but nothing will stop us now,” smiled Joe happily.

“You will be amazed when you look upon the wonders in the cave,” Dr. Rander told them. “It will exceed your wildest dream.”

“How did they all get there?” inquired Bob.

“I do not know. They were placed there by some wealthy Inca—perhaps a king—for safe keeping. It might have been that this was at the time of the Spanish invasion, and that the owner was later killed by the conquering troops. At any rate, the secret remained as such until I accidentally found it.”