Then, suddenly, his attention was caught by Fenno’s upraised voice. Joel, in the course of his sweeping survey of the country behind him, had chanced to drop his gaze to the hips of his sweating and welt-skinned mount. He saw the water bag and the bundle of rations were gone from behind his saddle. He was an old enough plainsman to realize what this implied. It meant he must go hungry until night--he who had ridden himself into such a hearty appetite. It meant, too, that he must do all his drinking from the muddy and perhaps alkaline puddle of the mile-distant waterhole; and that thereafter he must travel through the heat with unassuaged thirst until he should get back to the ranch at nightfall. Small wonder that he burst into a roar of red profanity! He knew well enough how the mischance had occurred. His spine still ached from the bucking of Pancho, four hours ago. It must have been during that series of jarring bucks that the water bag and the bundle had been loosened and had tumbled unheeded to earth. It was Pancho’s fault--all Pancho’s fault! In a gust of wrath, he slashed the mustang across the neck with his quirt. Now a horse is almost as quick as a dog to note a change in his master’s mood. Even before the blow--even before the burst of swearing--Pancho had become aware of a slackening in his rider’s wonted grim self-command. He had prepared, in his meanly uncertain mind, to take advantage of it. Before the quirt had fairly landed athwart his neck, Pancho had left ground. This time he did not buck. Straight up in air shot his forequarters. There was no warning of the outbreak. Moreover, Fenno had been sitting carelessly in the saddle; for the horse had been standing still. There was no scope for guarding against the trick. Scarce did the man’s knees seek to grip the pony, in anticipation of any plunge the quirt blow might entail, when Pancho reared. With the speed of light, the mustang flung his head and shoulders upward. In practically the same motion he hurled his tense body back; dashing himself to the ground, with his rider beneath him. More than once, in former battles, Pancho had attempted this, with Joel. But, usually a fist-thump between the ears had brought him down on all fours again before the ruse was complete. Failing to land such a punch, Fenno had at other times twisted out of the saddle and safely out of the falling body’s path, before the pony could strike ground. But, to-day, the outshot fist started its drive an instant too late. It grazed Pancho’s ear. Joel slipped from the saddle; but again a fraction of a second too late. Down crashed the nine-hundred-pound mustang, full on the helplessly struggling body of his fallen rider; pinning Fenno to earth on an outcrop of shale rock. With a snort and a wriggle, Pancho was up on his feet again. On the trampled ground behind him floundered a writhing and bruised man, who twisted like a stamped-on snake.