Diana snapped her fingers over her shoulder, a trick she had learned from a French officer in Biskra. "I said go!" she repeated sharply. She took no notice of his going and did not look back to see what orders he gave the men. She glanced at her watch again. Perhaps it was growing late, perhaps the camp was a longer ride than she had thought; but Mustafa Ali must learn his lesson if they rode till midnight to reach the oasis. She pushed her obstinate chin out further and then smiled again suddenly. She hoped that the night would fall before they reached their destination. There had been one or two moonlight riding picnics out from Biskra, and the glamour of the desert nights had gone to Diana's head. This riding into the unknown away from the noisy, chattering crowd who had spoiled the perfect stillness of the night would be infinitely more perfect. She gave a little sigh of regret as she thought of it. It was not really practical. Though she would wait nearly another hour to allow the fact of her authority to sink into Mustafa Ali's brain she would have to hasten afterwards to arrive at the camp before darkness set in. The men were unused to her ways and she to theirs. She would not have Stephens' help to-night; she would have to depend on herself to order everything as she wished it, and it was easier done in daylight. One hour would not make much difference. The horses had more in them than had been taken out of them this morning; they could be pushed along a bit faster with no harm happening to them. She eyed her watch from time to time with a grin of amusement, but suppressed the temptation to look and see how Mustafa Ali was taking it, for her action might be seen and misconstrued. When the time she had set herself was up she rose and walked slowly towards the group of Arabs. The guide's face was sullen, but she took no notice, and, when they started, motioned him to her side again with a reference to Biskra that provoked a flow of words. It was the last place she wanted to hear of, but it was one of which he spoke the readiest, and she knew it was not wise to allow him to remain silent to sulk. His ill-temper would evaporate with the sound of his own voice. She rode forward steadily, silent herself, busy with her own thoughts, heedless of the voice beside her, and unconscious of the fact when it became silent. She had been quite right about the capabilities of the horses. They responded without any apparent effort to the further demand made of them. The one in particular that Diana was riding moved in a swift, easy gallop that was the perfection of motion.