"Yeow!" howled the cowboys, but Grace did not hear them, for the pony had dropped to all fours, and no sooner had his feet touched the ground than he leaped clear of it, coming down stiff-legged with a jolt that jarred Grace Harlowe throughout her body in spite of her effort to soften the shock by throwing most of her weight on the stirrups. "He's going to buck," warned the steady voice of Hi Lang. Grace knew it in advance of the guide's warning, but, though she tugged with all her might, she was not strong enough to get the black bronco's head up so he could not carry out his intention. There followed a series of bucks and squeals, accompanied with flying hoofs, that sent the spectators fleeing for safety. As for the Overland girl, her head was spinning, her hair was down and her sombrero long since had fallen off and been trampled in the alkali dust by the hoofs of her mount. The jolting she was getting was almost more than she could endure and sharp pains were shooting through her body. This bronco indeed was a master at the art of bucking, but vicious as were his movements the black had not succeeded in ridding himself of his rider. "Look out!" yelled the guide. All four feet went from under the pony and he struck the ground on his side with a force that brought a grunt from him. In the cloud of dust the spectators thought that Grace had been caught under the horse and crashed. Emma Dean uttered a cry of alarm, and Nora Wingate turned her head away that she might not see. "She's all right!" shouted Hiram Lang, who had sprung forward to give assistance if it were needed. The pony had thrown itself on its right side. Mr. Lang found Grace sitting calmly on the side of the saddle, free of the body of the horse, but breathing heavily. Her quickness had been the means of her disengaging herself as the bronco threw himself to the ground. After giving the black a few seconds on his side, the Overland Rider brought her crop down on his rump with a vicious whack. It stung. Like a flash the pony was on his feet, with Grace's feet now planted firmly in the stirrups. As Grace had expected, the bucking was resumed the instant the pony felt the smart of the crop. How the dust did fly then, and how those cowboy wranglers did yell! "Who's a tenderfoot!" howled Hippy Wingate. "Just watch her smoke." Grace Harlowe's whole body was weary, but her grit was not diminishing in the least. However, she decided that the time had arrived when she must do a little fighting for herself, and not leave it all to the pony, so, having arrived at this decision, Grace watched narrowly for a favorable opportunity to begin. The opportunity came a few seconds later when the horse threw up his head preparatory to pitching forward in another series of savage bucks. Grace jerked the animal's head to one side, brought her quirt down sharply, and, at the same time, jabbed the little black fighter with her spurs.