"What can't you stand?" he asked.

"It is Captain Tavernay," replied Barbier. He suddenly laughed in a pitiful fashion, and cast a glance over his shoulder. "There is a man put on to watch me. Night and day I am watched by Captain Tavernay's orders. He wants to fix a crime on me! I know. He wants to trap me. But let him take care!"

Stretton fetched the doctor, who listened for a while to Barbier's rambling, minatory talk, and then shrugged his shoulders.

"Hallucinations," said he. "Ideas of persecution. The commonest form," and having fixed Barbier into his proper category, he walked away. There was nothing to be done for Barbier upon this expedition. He had to be watched; that was all. Thus for seven hundred miles the force pushed southwards from Ouargla, and thus from within it disintegrated as it went. Tavernay could not but notice the change, but he said nothing to any subordinate. The men would fight well if fighting happened. That he knew, and meanwhile he marched on.

It was just when the seven hundred miles had been completed that Tavernay realised fighting was likely to happen. He went the round of the camp as the sun was setting, when the rifles were piled and the fires crackling. Stretton was at his side, and saw his commander stop and shade his eyes. Tavernay was looking westwards. Far away against the glowing ball of the sun, which was just dipping down behind the plain, the figure of an Arab mounted upon a camel stood motionless and black. Tavernay swung round and looked behind him. On the crest of a sandhill to the north a second rider stood distinct against the sky.

Tavernay watched the men for a long time through his glasses.

"Touaregs," said he, gravely. "Masked Touaregs," and that night the sentinels were doubled; and in the morning the bugle did not sound the réveillé.

Moreover, when the force advanced, it advanced in the formation of a square, with the baggage camels in the centre, one gun in the front line, and the other in the rear. They had marched into the country where the Senoussa sect prevailed. The monasteries of that body sent out their missionaries eastward to Khordofan, westwards to Tafilet, preaching the purification of the Mohammedan religion and the enlargement of Mohammedan countries now subject to the infidels. But nowhere had the missionaries raised their standard with more success than in this Touat country of the Sahara. The companies marched that day alert and cheerful. They were consolidated by the knowledge of danger. Captain Tavernay led them with pride.

"An insufficient force, ill-found, inadequately officered," he thought. "But the men are of the Legion." They were mes enfants to him all that day.

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.