“Oh, do. I should so like to have one for a pet,” cried Mabel.

It seemed, however, that the jerboa preferred freedom to captivity, even with Mabel as jailer, for it was gone in a moment, getting over the ground in tremendous leaps, at a pace which taxed the horses sorely to keep up with it.

“Oh, it’s getting away!” lamented Mabel.

“Perhaps I can manage to wing him from here,” said Fitz, bringing out his revolver. “We could easily patch up a broken leg. Steady, Sheikh, old boy!”

The pace was fast and the ground rough, and it was scarcely surprising that the jerboa escaped unscathed, but Fitz’s shot had an effect that he had not anticipated. At the sound Mabel’s little mare stopped dead with a suddenness which jerked the rider’s foot from the stirrup and nearly threw her out of the saddle, then took the bit in her teeth and dashed away in a frenzy of terror. Pull as she might, Mabel could not stop her, nor could she get her foot again into the stirrup. The horror of that wild rush through the whirling sand-clouds, with the wind shrieking in her ears, was such as she could never have imagined. Certain destruction seemed to be before her, for Laili was heading straight for the rocky ground at the foot of the mountains, where there was no hope that she would be able to keep her footing. Mabel was dimly conscious that she ought to come to some decision, or at least to select a moment at which to throw herself off, but all her powers seemed to be concentrated in the effort to pull up, or at any rate to turn the pony’s head towards the open desert. As it was, Laili made the decision for her. An isolated rock, revealed unexpectedly by a lull in the wind, which caused the drifting sand to settle for a moment, stood on the left hand of the course she was taking, and catching sight of it, she swerved away so violently that Mabel found herself all at once in a sitting position upon the sand. There she remained, too much dazed to make any attempt to rise, until Fitz dashed up, and flung himself recklessly from his horse, which promptly continued the chase of the runaway on its own account.

“Oh, thank God you are not killed!” he cried brokenly to Mabel, his sunburnt face ghastly pale. “But you are frightfully hurt! What is it—your back? Oh, for Heaven’s sake, Miss North, try to move! Is your leg broken? Don’t say it’s your back!”

Mabel repressed a weak desire to laugh. “I—I think I’m sitting here because you haven’t offered to help me up,” she replied, as well as her chattering teeth would let her.

He helped her up in silence, and began mechanically to brush the dust from her habit with shaking hands. When at last he looked up at her, Mabel saw that his lips were still trembling, and his eyes full of horror.

“Oh, don’t look like that about me!” she cried impulsively. “I’m not worth it.”

“Not worth it?” he cried violently, then, controlling himself with an effort, he made a fair attempt at a laugh. “If anything had happened to you, I should never have dared to face the Major and Mrs North again,” he said. “Or rather, I could not have faced my own thoughts.”