Blue Bonnet looked up in speechless surprise; Sarah was certainly "coming on." "Surely you may," she said cordially, straightway handing over the reins. "Hold them firmly--these colts are apt to run under a loose rein." Sarah felt a curious sense of power as she grasped the leather in her unpracticed hands. Conscientious to a degree, she did as she was bid and held the mustangs firmly. In her anxiety to do the thing properly, she overdid it, and the next moment the horses were tossing their heads angrily and backing with all their might. The bank of the stream just here was very high and steep, though just beyond was a ford where the road branched. The light buckboard offered no resistance to the spirited mustangs, and, in a second, before Blue Bonnet could grasp the reins, one hind wheel had slipped an inch or two over the ledge. For a second or two the girls were in grave danger. Blue Bonnet felt a swift overpowering fear; the half-broken colts were as apt to plunge backward as to advance if they felt the whip, and that meant a plunge down the steep bank. She looked about her helplessly. Sarah, with a faint shriek, shut her eyes and prepared for the catastrophe. At that moment a horseman came suddenly up the bank at the ford, emerging as if from out the earth. At a glance he took in the situation, was off his horse, caught the near colt by the bit and brought both frightened animals to a standstill with the wheel a safe margin from the bank. Then without waiting to hear the faintly murmured thanks of the terrified girls, their rescuer turned at once to his own horse, which had seized the moment to make a break for freedom. The boy--for he was hardly more--had thrown the lines over the animal's head and now, with another of his incredibly swift movements, he caught them and in a second more had jerked the horse about. Then in a flash he was once more in the saddle. Blue Bonnet had just managed to catch her breath,--when it was taken away again. For before the boy had put his right foot in the stirrup, he was out of the saddle once more, lying all of a heap in the grass, while his horse with a wicked kick-up of his heels, vanished around a turn in the road. Not daring to trust the reins out of her hands a second time, Blue Bonnet almost pushed Sarah from her seat. Fearfully the girl approached and bent over the fallen hero; to her relief she saw that his eyes were open. He blinked queerly for a moment, then gave a gaspy little laugh. "I'm all right. Don't worry. It's knocked the breath out of me--that's all," he managed to say at last; and then, after another pause, he scrambled up to a sitting posture. "I'm so sorry," said Sarah, finding her voice. "I hope you're not seriously hurt." "I'm--quite whole!" he assured her, and stopped with a wince of pain. "It's my wrist, I reckon--broken or sprained." He examined the injured member closely and after a vain attempt to lift it said briefly: "Broken. Isn't that the limit?"