There were cries of astonishment from the others. For the past few days the thought of the thieves had been absent from their minds. Now they began to realize that at last they had probably come into the region in which were the hidden riches. "Then the rascals must be around here some place," said Joe, looking about sharply. "Perhaps they're right around here." Fekmah got out the map he had made from memory after the original one had been stolen. He studied it closely for a few minutes. "Hidden treasure still great distance away," he said at last. "We not find it till several days pass. I think the two thieves not here but somewhere near treasure." "What's the next landmark?" inquired Mr. Lewis, as the camels were made to move forward. "The gorge of Arak," Fekmah returned. "It quite a distance from here, but Tishmak lead us to it quickly." All morning they trudged on without coming to the well that Tishmak knew was somewhere in the first range of mountains. Although it seemed impossible, their thirst rapidly increased still more. "Say," cried Bob, as a sudden thought struck him, "if those two thieves could cover up the first mountain well, they might do the same to others. Wouldn't it be possible?" "Not the next one," returned Fekmah. "It too large. Take many, many men to stop it. But there are several small ones farther on that could be covered." At an hour before noon it was necessary to stop for the daily rest, even though they would have liked to continue in search of water. They were in a narrow valley between tall, sharp peaks. A ribbon-like dry river bed wound in and out among the brightly colored rocks, suggesting that once a rushing stream had forced its way through the mountains. "How I wish the river were still here," said Joe with a sigh. As soon as camp was made, the explorers took it easy in the shade of the tent, more than glad to escape the terrible heat of the sun. But before long Bob and Joe became restless. At last Joe got up and stretched. He sipped a very small quantity of water; then motioned for Bob to get up. "What's up?" the latter asked. "Come on," said Joe, picking up his rifle. "Let's go out awhile. I'm anxious to explore these mountains around here. There's no telling what we may come across." Bob was willing, and as the sun was slightly less hot, they started out in the direction of a large mountain that had tall, sharp points reaching up into the sky. "What's that over there?" asked Bob, pointing to a wall of rock some two hundred feet away. "Don't know. Let's go over and see." The youths walked over to the precipice and then halted before a small crack that looked to be the entrance to a cave. "Shall we go in?" asked Joe. "I'm game. Come on." The hole in the rock was so small that it was necessary to crawl on their hands and knees for a short distance. Then the cave became larger, and they could stand. Bob had his flashlight in his pocket and at once switched on the light.