But the attack was not yet to be delivered. During the night the two scouts had ridden on their swift Meharis northwestwards, to the town of Insalah. They knocked upon the gates of the great mud fortress of Abd-el-Kader, the sheikh, and were instantly admitted to the dark room where he sat upon a pile of rugs. When the eyes of the scouts became accustomed to the gloom, they saw there was yet another in the room, a tall man robed in black, with a black mask of cotton wound about his face so that only his eyes were visible. This was the chieftain of the Hoggar Touaregs. "Well?" said Abd-el-Kader. And the scouts told him roughly the number of the force and the direction of the journey. Then Abd-el-Kader turned to the Touareg chieftain. "We will let them go further south, since southwards they are marching," he said, in his suave gentle voice. "A hundred miles more, and they will be amongst the sand dunes. Since they have cannon, the attack must be sudden. Let it be at the wells of Bir-el-Gharamo." The Touareg chieftain rode out that day towards his hills; and, unmolested, Captain Tavernay's expedition went down to the dunes. Great waves of yellow sand, sometimes three hundred feet from crest to base, intersected the face of the desert; the winds had given to their summits the overhang of a breaking sea; they ran this way and that, as though the currents of an ocean had directed their course; they had the very look of motion; so that Stretton could not but remember the roaring combers of the cold North Sea as he gazed upon these silent and arrested copies. They made of that country a maze of intricate valleys. Led by a local guide commandeered from the last oasis, the companies of the Legion marched into the maze, and on the second day saw, as they came over a hill, just below them in a narrow hollow, a mud parapet built about the mouth of a well. This was Bir-el-Gharamo, and here they camped. Sentries were posted on the neighbouring crests; suddenly the darkness came, and overhead the stars rushed down towards the earth. There was no moon that night, nor was there any sound of danger heard. Three times Tavernay went the round of the sentries, at eight and at ten and at twelve. But at three o'clock, just as the dawn was breaking, a shot was heard. Tavernay sprang up from the ground, the alarm rang out clear from the bugle over the infinite waste, the companies of the Legion seized their piled rifles and fell into battle order with an incredible neatness and expedition. There was no confusion, no noise. The square was formed about the well--the camels were knee-haltered in the middle, the guns placed at the corners. But it was still dark. A few shots were fired on the dunes, and the sentries came running back. "Steady," cried Captain Tavernay. "They are coming. Fire low!"