"Why?" She tried to keep silent, but the question was forced from her, and she waited tense for his answer. Tales of ruthless Arab cruelty surged through her mind. What had been the fate of the unfortunate caravan leader? Her eyes closed and her throat grew dry. "There was no need for any murder," he continued sarcastically. "When you come to know me better you will realise that I do not leave too much to chance. 'All things are with Allah, blessed be his name.' Good! But it is well to remember that Allah does not always concern himself with the affairs of men, and arrange accordingly. If I had left this affair to chance there might very easily have been, as you suggest, murder done--though we do not call it murder in the desert. It was very simple. _Voyons_! You paid Mustafa Ali well to guide you in the desert. I paid him better to lead you to me. I paid him well enough to make him content to remove himself from Biskra, where awkward questions might be asked, to another sphere of usefulness where he is not known, and where he can build up for himself a new reputation as a caravan leader." There was another silence and her hands went groping to her throat. It had been no chance affair then--no accidental meeting that the Arab chief had turned to his own account, but an organised outrage that had been carefully planned from the beginning. From the very outset she had been a dupe. She ground her teeth with rage. Her suave, subservient guide had been leading her the whole time, not in the direction that had been mapped out in Biskra, but towards the man who had bought him to betray his trust. Mustafa Ali's shifting eyes, his desire to hurry her from the oasis where they had rested at mid-day, his tone were all explained. He had acted well. The last touch--the imaginary wound that had toppled him slowly out of his saddle had been a masterpiece, she reflected bitterly. Nothing had been omitted to make the attempt a success. The horse that had been given her to ride was the Sheik's beyond all doubt, trained to his whistle. Even her revolver had been tampered with. She had not missed, as she had thought. She remembered the noise, the fleeting vision she had had in the hotel at Biskra. It had been some one in her room, Mustafa Ali himself, or one of his men, who had stolen in and substituted the blank cartridges. The possibility of Aubrey changing his mind and accompanying her must also have been thought of, for the Sheik had provided against the resistance that would certainly have then been made by the number of followers he had brought with him--a large enough force to frustrate easily any attempted opposition to the attack.