Tishmak unstrapped his rifle and motioned for the others to do likewise. "Wonder if it's bandits," muttered Joe, holding his gun in readiness. The sound of camels' footsteps now reached the adventurers' ears. Then from behind a hill appeared a long trading caravan of Arabs, who also had their rifles in readiness. Tishmak rushed forward, throwing his hands apart in a gesture of friendliness. He was followed by Fekmah and the others. As soon as the Arabs saw that the whites meant no harm, they stopped and talked freely. Much to Dr. Kirshner's delight, he could understand the men easily, their language differing greatly from that of Tishmak. The Americans learned that the caravan was on its way to Wargla, loaded with a large supply of dried dates, grapes, and many other products of the desert oases. It was made up of over seven hundred camels, which were in a line several miles long. "Look at the leader," said Joe to his chum, referring to the head camel. "It's decorated with about as many colors as there are." "Want to make a good showing," smiled Bob. "From what I've heard, a caravan is judged by how well the first camel is engulfed by colors." Much as the explorers would have liked to talk with the Arabs, they did not stop long. Time was too valuable to be wasted, especially when they were literally running a race with the two thieves who had stolen Fekmah's map. But before they left, Bob and Joe took motion pictures of the caravan at several distances. Especially were the youths pleased by the friendly attitude of the Arabs when the camera was held before them. "Doubt if they know what it's all about," smiled Bob. "But that doesn't keep the pictures from being good." "Wouldn't they be surprised if they could see themselves on the screen!" laughed Joe. "They'd probably think something supernatural was taking place." With a cheery farewell the American expedition left the Arabs at the head of the trading caravan and again took up the journey. But it required nearly a half-hour to pass the last of the pack camels, which were guarded at intervals of every fifty animals by an armed Arab. "Seven hundred camels is a good many," remarked Bob, as the youths rode at the rear of their own pack animals. "Their owner must have a good bit of money." "Many of those Arabs are wealthy, I guess," said Joe. "Fekmah said some have as many as two thousand camels." As the explorers moved on, they saw other signs of small game. Occasionally Mr. Holton and Mr. Lewis displayed their skill with a rifle by shooting creatures from a great distance. "Seems to be getting a little darker," remarked Joe, as they descended into a little valley. "Darker? Couldn't be." Then, as Bob gazed ahead at the opposite slope, he uttered an exclamation of bewilderment. "It _is_ getting darker!" he cried. "Why--why, it's impossible. Dark at nine in the morning! Something's wrong somewhere!" A second later Mr. Holton rode up to the boys anxiously.