"It would be as well to find that out, Sidi. Do you give me two of your best mounted men and then ride straight on with the others. We will remain here till they approach, and then ride on for another eight or ten miles, still keeping them in sight. They will assuredly camp at the wells of Orab if they are making for the oasis. These are about twenty miles from the Nile, and they will go no further to-day, for it is as much again before they come to another well. When we have with certainty made out that they are making for the wells of Orab, we will follow you at full speed, but do not wait for us, and, save to give your horses a drink, do not draw rein till you reach your people and deliver your father's message. I don't suppose that I shall overtake you before you get there, but I shall not be long after you, and my report may decide him what he had best do."

Sidi at once picked out two men who were, he knew, among the best mounted of the tribe, and told them to remain with Edgar and act under his orders. Then at a much more rapid pace than before he pursued his journey. Edgar and his men dismounted, sitting down on the sands until the French were again within a mile of them, then they cantered on ahead. The French had followed so exactly the line along which the party had ridden that Edgar felt quite convinced that they were making for the wells. However, he kept at the same distance ahead of them until the Arabs told him that they were now within five miles of the water.

"Then we will go on," he said. "It is certain now that they are going there, and as you say there are no camping grounds within many miles of the wells, I think it is certain that they are bound for the oasis of the Beni Ouafy."

They now rode at full speed to the wells. Here for a quarter of an hour they halted, refilled their water-skins, gave the horses a drink and a handful of dried dates, eat a few themselves, and then started on their long ride. Had not Edgar had perfect confidence in the Arabs' knowledge of the country he would have felt uneasy, as hour after hour they rode across wastes of sand without, so far as he could see, any landmark whatever to guide their course. He remarked this to them. Both smiled.

"You Franks can make your way over the sea when there is nothing whatever to guide you," one of the men said; "it would be strange if we could not do the same over the land that we have traversed many times before."

"At sea they have a compass with a needle that points always to the north, so that they know in what direction they are going."

"We have the sun," one of the Arabs answered; "but even without that we could find our way, and do so even on the darkest night. The horses know the way as well as we do. When they have once journeyed over a track they never forget it, and even did they swerve a little it would not matter, for they can smell water miles away, and would always, if unguided, make for it."

At ten in the evening Edgar rode into the Bedouins' encampment, having passed over eighty miles since leaving the Pyramid. Sidi's party had arrived there half an hour earlier, and he found that his friend was now in the tent of the sheik. Edgar went there at once, and Sidi introduced him to his uncle, who was some years older than his father.

"I am rejoiced to see you," the sheik said gravely. "I heard how you had before befriended Sidi, and the messenger who arrived here told us how you had saved the lives of my brother and nephew, and I wanted to see your face.

"Truly you are young, indeed, to have done such wonderful deeds, and to have so much wisdom, as well as courage. Sidi tells me that some fifteen hundred of the Frankish cavalry are riding hither."