As for Mabel, she felt it distinctly hard to be obliged to sacrifice herself in this way for Flora’s benefit. Mr Brendon, of the Public Works Department, was a most estimable young man, but he suffered from a plethora of useful knowledge. To ask him a question was like pulling the string of a shower-bath, which let loose a flood of information on the head of the unwary questioner. Mabel had intended to let him prose as he liked, while she thought about other things, and jerked the string, so to speak, at the requisite intervals, but he was far too polite to monopolise the conversation. He paused for her replies or invited her opinion so often, while clearly ready to supply the needed answer himself, that she had not a moment for meditation, and found the ride almost unendurable. She had just succeeded in hiding an irrepressible yawn when a happy idea came to her as she was approaching a state of desperation.

“Oh, here is quite a nice level piece of ground! Let us race, Mr Brendon.”

He could not well refuse, and for all too short a time Roy pounded gallantly through the sand. Brendon’s lighter steed won easily, and when Mabel reached the end of the course, she found him waiting for her. At this point their road entered a narrow ravine, leading down to the open desert, and the high rocks on either side looked black and threatening against the glowing sunset sky, a glimpse of which at the farther end of the gorge dazzled the eyes.

“I think you had better let me pilot you here, Miss North,” said Brendon. “The ground is strewn with loose boulders, and it is difficult to distinguish them in this light. You might get a nasty fall.”

It was desirable that Brendon should ride anywhere rather than beside her, and Mabel accepted the position he assigned to her with something more than resignation. He took the lead as they entered the ravine, his pony picking its way with infinite caution, and Roy followed securely enough.

“What a delightful Dürer engraving we should make!” exclaimed Mabel suddenly, “creeping along between these dark cliffs under such a gorgeous red sky. But it’s contrary to all symbolism that you should be riding first.”

“The colour of the sky would scarcely tell in an engraving,” answered Brendon, with a perceptible accent of reproof. “But the idea would work out well in black and white.”

“Oh dear, no!” persisted Mabel. “The sky is everything. It gives such a threatening touch. I feel quite weird myself, don’t——”

“Don’t you?” she was going to say, but the words were cut short, for a shot was fired among the rocks on the left, close beside her. Roy, accustomed to such sounds, merely started slightly and pricked up his ears, but the pony shied violently, and received a cut from its rider.

“Abominable carelessness!” shouted Brendon to Mabel, looking round as the animal dashed forward. “I’m coming back to hunt that fellow out. He might have shot one of us.”