The small life of the plain was fleeing before the furnace-like breath of those red, surging clouds. Jackrabbits leaped across the road on fleet legs, and occasionally Conrad saw coyotes, singly or in packs, running eastward as for their lives. Fat carrion crows hurried their unwieldy flight and, higher in the air, a frequent lone hawk sailed out of the west, while now and then a road-runner cut across his path with hasting feet. "It's going to be a bad one, I guess," Curtis muttered, jamming his soft hat down closer on his head. The mare seemed to be trying of her own accord to escape the storm, and her swinging lope was steadily leaving the miles behind. "Keep it up, Betty, keep it up," he said encouragingly. "I want to reach Adobe Springs and get this message to Baxter off my mind. My shoulder's aching, old girl, but it ain't aching a bit more than I am to tell him what I think of him." Soon the sand-storm was upon them, concealing the landscape and covering the sky with its clouds. Upon man and beast it beat as bitterly as a sand-blast. It pelted and stung Conrad's face and neck, and filled his eyes and ears and nostrils until he was forced now and again to pull his hat over his face for a moment's respite in which to draw a less choking breath. "It looks as if all Arizona had got up and dusted, and was hell-bent to get out of here," he jested grimly, as he bent over the mare's neck and encouraged her with voice and gentle stroke. "That shows good sense, Betty, though it's mighty hard on us. Come right along, old girl; we must get to Adobe Springs." [Illustration: "UPON MAN AND BEAST THE SAND-STORM BEAT BITTERLY"] As the air grew thicker there shone from the sky, instead of the vivid white sunshine of a few hours before, only a dim, diffused, lurid light. Even to Curtis, sitting quartering in the saddle with his back twisted toward the wind, Brown Betty's ears were barely visible. For a while he allowed the mare to follow the road herself, until he found that her sense of duty must be supplemented by authority. For, under the discomfort of the belaboring wind and stinging sand, she began to yield to her instinct to turn tail and drift before the storm. Then he knew that he must keep a firm hand on the bridle, and his attention at the highest pitch, or they would soon be wandering helplessly over the plain. He walked long distances beside the mare, with his body shielding her head and with speech and caress keeping up her courage. Their progress was slow, for the force of the storm was so great that, though it beat against them from the side, they could struggle through it only at a walk.