It was the whirring flight of a startled dove that told Bannister the whereabouts of his foe. Two hundred yards from him the bird rose, and the direction it took showed that the man must have been trailing forward from the opposite quarter. The sheepman slipped back into the dry creek bed, retraced his steps for about a stone-throw, and again crawled up the bank. For a long time he lay face down in the grass, his gaze riveted to the spot where he knew his opponent to be hidden. A faint rustle not born of the wind stirred the sage. Still Bannister waited. A less experienced plainsman would have blazed away and exposed his own position. But not this young man with the steel-wire nerves. Silent as the coming of dusk, no breaking twig or displaced brush betrayed his self-contained presence. Something in the clump he watched wriggled forward and showed indistinctly through an opening in the underscrub. He whipped his rifle into position and fired twice. The huddled brown mass lurched forward and disappeared. “Wonder if I got him? Seems to me I couldn’t have missed clean,” thought Bannister. Silence as before, vast and unbroken. A scramble of running feet tearing a path through the brush, a crouching body showing darkly for an eyeflash, and then the pounding of a horse’s retreating feet. Bannister leaped up, ran lightly across the intervening space, and with his repeater took a potshot at the galloping horseman. “Missed!” he muttered, and at once gave a sharp whistle that brought his pony to him on the trot. He vaulted to the saddle and gave chase. It was rough going, but nothing in reason can stop a cow-pony. As sure footed as a mountain goat, as good a climber almost as a cat, Buck followed the flying horseman over perilous rock rims and across deep-cut creek beds. Pantherlike he climbed up the steep creek sides without hesitation, for the round-up had taught him never to falter at stiff going so long as his rider put him at it. It was while he was clambering out of the sheer sides of a wash that Bannister made a discovery. The man he pursued was wounded. Something in the manner of the fellow’s riding had suggested this to him, but a drop of blood splashed on a stone that happened to meet his eye made the surmise a certainty. He was gaining now—not fast, almost imperceptibly, but none the less surely. He could see the man looking over his shoulder, once, twice, and then again, with that hurried, fearful glance that measures the approach of retribution. Barring accidents, the man was his. But the unforeseen happened. Buck stepped in the hole of a prairie dog and went down. Over his head flew the rider like a stone from a catapult. How long Ned Bannister lay unconscious he never knew. But when he came to himself it was none too soon. He sat up dizzily and passed his hand over his head. Something had happened.