The yells behind them stopped.  But after some moments they heard a camel snarl, and knew that some one was still back there in the darkness, hanging on their trail.  So they rode hard ahead, into the enveloping night, over the rolling dunes, with the wind leaping and tearing and hurling the sand in their faces, as if the very elements were fighting against them.

It was a strange chase and a hot one, pounding on and on, racked with the wild, lurching flight, deeper and deeper into the yellow-gray night that welcomed them with more strident blasts and more stinging particles of sand.

“It’s a storm,” Billy shouted at her, raising his voice above the wind.  “It’s been blowing up this way for an hour now—­they won’t follow long in the face of it.  Can you hang on a little longer?”

“Forever,” she cried back, gripping the pommel tight and bending her head before the whirling particles.  There was sand in her hair, sand on her lashes and in her eyes, sand on her face and down her neck, and sand in her mouth when she wet her lips, but she heard herself laughing in the night.

“By and by we’ll get off,” he called back, and by and by when the hot, stifling, stinging, choking, whirling gale was too blinding to be borne, he checked the camels in one of the hollows of the desert dunes from which the wind was skimming ammunition for its peppery assaults, and the beasts knelt with a haste that spoke of gladness.

“It’s the backbone of it now; cover your head and lie down,” Billy commanded, and Arlee covered it with what he thrust into her hands—­his overcoat, she found—­and tucked herself down against him as he crouched beside the camels.

“I should think—­it was—­the backbone,” she gasped, unheard, into her muffling coat.  For the wind howled now like a rampaging demon; it tore at them in hot anger; it dragged at the coat about her head, and when her clutch resisted, it flung the sand over and over her till she lay half buried and choking.  And then, very slowly and sulkily, it retreated, blowing fainter and fainter, but slipping back for a last spiteful gust whenever she thought it finally gone, but at last her head came out from its burrow, and she began cautiously to wipe the sand crust off her face and lashes.

“In your eyes?” said a sympathetic voice.

In the darkness beside her Billy Hill was sitting up, digging at his countenance.

“Not now—­I’ve cried—­that all gone,” she panted back.

He chuckled.  “I’ll try it—­swearing’s no use.”

She sat up suddenly.  “Are they coming?”

“Not a bit.  No use, if they did.  You’re safe now.”

“Oh, my soul!” She drew a long, long breath.  “I can’t believe it.”  Then she whirled about on him.  “How—­why—­why is it you?”

He looked suddenly embarrassed, but the darkness hid it from her.  He became oddly intent on brushing his clothes.  “Oh, I guessed,” he said in a casual tone.