Through the early part of the night they rode ever on, on toward the mysterious Ahaggars. One question stood out in the minds of all. What did the future hold in store? Finally Tishmak brought his dromedary to a halt beside a huge boulder. He motioned for the others to follow suit. "We'll stop here for the night," announced Fekmah, after conversing with the guide. "But we must be up very early in morning and get on way to mountains." That night everyone slept soundly, anxious to refresh themselves thoroughly for the tiresome march through the Ahaggars. "Let's go," urged Joe, as he dressed the next morning at dawn. "We can't get to those hidden riches any too soon for me." Mr. Holton laughed unwillingly. "Who ever heard of fast traveling in the mountains?" he asked. "If we make ten or fifteen miles in a day we'll be lucky." "There are stretches of smooth country, though," Dr. Kirshner put in. "And when we get to the central plateau of the Ahaggars, it won't be so hard to cover territory." A breakfast of limited food but a bountiful supply of water was prepared by Mr. Lewis, and then camp was broken. In the early-morning light the peaks ahead looked pale purple, but, said Fekmah, this color would gradually change to mauve and blue as the sunlight became more radiant. As they rounded a tall, red boulder, Tishmak suddenly halted his camel and pointed to a little crevice between the rocks. "Well, as I live!" murmured the archæologist in surprise. "Camels--dead, mummified camels." The beasts had evidently been dead a long time, for their skins were extremely dry and cracked. The fierce desert sun had preserved their bodies for an indefinite period. "And look, they've got their mouths down to the ground, as if they were searching for water," observed Joe. "They were," affirmed Fekmah. "There once a well here, but it dried up just before camels got to it." "Perhaps they wandered for days searching for it, and then finally found it--dry." Bob shuddered. It was a pitiable sight, particularly to the Americans. They half expected to come across the mummified body of some unfortunate explorer who had died a tragic death from thirst. "We must be doubly careful to have the containers filled with water," warned Mr. Holton. "This is a dangerous region, and disaster could easily come upon our little expedition." They trudged on in the rapidly rising temperature of the terrible sun, keeping their eyes off the ground as much as possible to escape the glare. They could easily have worn sun glasses, but hesitated to do so because of the rather obstructed vision. "What's this!" cried Dr. Kirshner, as they came to a huge rock that was directly in their path. "Some kind of an inscription, isn't it?" inquired Bob.