"Ride on," said Mackenzie. Mrs. Carlson urged her horse with sudden start close to where Joan stood, leaned far over her saddle and peered into the girl's face. Joan, affronted by the savage impertinence, met her eyes defiantly, not giving an inch before the unexpected charge. In that pose of defiant challenge Swan Carlson's woman peered into the face of the girl whose freshness and beauty had drawn the wild banter from her man's bold lips. Then, a sudden sweep of passion in her face, she lifted her rawhide quirt and struck Joan a bitter blow across the shoulder and neck. Mackenzie sprang between them, but Mrs. Carlson, her defiance passed in that one blow, did not follow it up. Swan opened wide his great mouth and pealed out his roaring laughter, not a line of mirth softening in his face, not a gleam of it in his eyes. It was a sound without a note to express human warmth, or human satisfaction. Joan flamed up like a match in oil. She dropped her bridle-reins, springing back a quick step, turning her eyes about for some weapon by which she might retaliate. Hector Hall's pistols hung on the end-gate of the sheep-wagon not more than twenty feet away. It seemed that Joan covered the distance in a bound, snatched one of the guns and fired. Her own horse stood between her and the wild range woman, which perhaps accounted for her miss. Mackenzie was holding her wrist before she could shoot again. Swan let out another roar of heartless laughter, and together with his woman galloped down the hill. Ahead of them the sheep were assembled, packed close in their huddling way of seeking comfort and courage in numbers, just beginning to compose themselves for the night. Straight into the flock Swan Carlson and his woman rode, trampling such as could not rise and leap aside, crushing such lambs as were not nimble enough or wise enough to run. "I'll kill her, I'll kill her!" said Joan. She panted, half crying, struggling to free her arm that she might fire again. "All right, let 'em have it!" Mackenzie said, seeing the havoc among the sheep. Swan and his woman rode like a whirlwind through the flock, the dogs after them with sharp cries, the frightened bleating of the lambs, the beating of two thousand hoofs, adding to the confusion of what had been a peaceful pastoral scene but a few minutes before. Joan cut loose at the disturbers of this peace, emptying the revolver quickly, but without effect. Half way through the herd Swan leaned down and caught a lamb by the leg, swung it around his head as lightly as a man would wave his hat, and rode on with it in savage triumph. Mackenzie snatched the rifle from the wagon. His shot came so close to Swan that he dropped the lamb. The woman fell behind Swan, interposing herself as a shield, and in this formation they rode on, sweeping down the narrow thread of green valley, galloping wildly away into the sanctuary of the hills.