She had ridden with Gaston, and hurried over her solitary dinner, and since then she had been waiting for the Sheik to come back. In what mood would he come? Since Raoul's announcement of his departure he had been more than usually taciturn and reserved. The book she held slipped at length on to the floor, and she let it he unheeded. The usual stillness of the desert seemed to-night unusually still-sinister even—and the silence was so intense that the sudden squeal of a stallion a little distance away made her start with madly racing heart Earlier in the evening a tom-tom had been going persistently in the men's lines, and later a native pipe had shrilled thinly in monotonous cadence; but she had grown accustomed to these sounds; they were of nightly occurrence and they soothed rather than irritated her, and when they stopped the quiet had become intensified to such a degree that she would have welcomed any sound. To-night her nerves were on edge. She was restless and excited, and her thoughts were chaos.