But the cut of the quirt transformed Diablo. If he had fought hard before, he now fell into a truly demoniacal frenzy. The long flashing legs were springs indeed, and the moment his hoofs struck the earth he was flung up again to a greater height. He was sunfishing now in that most deadly manner when the horse lands on one forehoof, the rider receiving a double jar from the down-shock and then the whiplash snap to the side. Hal Dunbar was no longer using his quirt. It dangled idly at his side. The joy had gone from his face. In its place, as shock after shock benumbed his brain, there was an expression of fierce despair. Neither was he riding straight up, but he was pulling leather. Otherwise, nothing human could have retained a seat in the saddle for an instant. Diablo, squealing, snorting, and grunting with effort, was dashing back and forth, flinging himself aloft, coming down on one stiff leg, doubling back with jackrabbit agility. There was no longer applause from the onlookers. Old Bridewell himself in all of his years had never seen riding such as this, and it seemed that Diablo at last had met his master. Never had he fought as he fought now; never had he been stayed with as he was now. With foam and sweat the great black was reeking, but never once were the efforts relaxed. It was too terrible a sight to be applauded. Then, at the end of a run, instead of hurling himself into the air as he had usually done before, Diablo flung himself down and rolled. It caught Dunbar by surprise, but the yell of horror from the bystanders stimulated him to sharp action, and he was out of the saddle in the last hair's breadth of time. Diablo had been carried on over to his feet by the impetus of the fall, and he was already rising when Dunbar leaped for the saddle. Fair and true he struck the saddle and with marvelous skill his left foot caught the stirrup and clung to it--but the right foot missed its aim, and, before Dunbar could lodge his foot squarely, the stirrup was dancing crazily as Diablo began a wild combination of cross-bucking and sunfishing. The hat snapped from the head of Dunbar and his long black hair tossed; with both hands he was clinging. All joy of battle was gone from him. In its place was staring fear, for his right foot was still out of the stirrup. "Choke him down! Choke him--" he shrieked. Before he could be obeyed by his confused henchmen, Diablo shot into the air and at the very crest of his rise, bucked. Dunbar lurched to one side. There was a groan from the bystanders; and the next instant the stallion, landing on the one stiffened foreleg, had snapped his rider from the saddle and hurled him to the ground. He lay in a shapeless heap, and the stallion whirled to finish his enemy. CHAPTER 18