Masten looked back frequently now. The grim, relentless figure behind him grew grotesque and gigantic in his thoughts, and once, when he felt the pony beneath him go to its knees, he screamed hysterically. But the pony clambered to its feet again and staggered on, to fall again a minute later. Catherson's pony, its strength conserved for this ordeal, came on steadily, its rider carefully avoiding the soft sand, profiting by Masten's experiences with it. It was not until he saw Catherson within fifty feet of him that Masten divined that he was not to be shot. For at that distance he made a fair target, and Catherson made no movement toward his gun. The nester was still silent; he had spoken no word. He spoke none now, as he hung relentlessly to his prey, seeming, to Masten's distorted mind and vision, a hideous, unnatural and ghastly figure of death. Catherson had drawn nearer. He was not more than thirty feet away when Masten's pony went down again. It fell with a looseness and finality that told Masten of the end. And Masten slipped his feet out of the stirrups, throwing himself free and alighting on his hands and knees in front of the exhausted animal. He got up, and started to run, desperately, sobbing, his lips slavering from terror. But he turned, after running a few feet, to see Catherson coming after him. The nester was uncoiling a rope from his saddle horn, and at this sight Masten shrieked and went to his knees. He heard an answering laugh from Catherson, short, malevolent. And then the rope swished out, its loop widening and writhing. Masten shrieked again, and threw up his hands impotently. * * * * * Later, Catherson brought his pony to a halt, far from where the rope had been cast, and looked grimly down at his fellow being, prone and motionless in the deep sand at his feet. Unmoved, remorseless, Catherson had cut short the pleadings, the screaming, the promises. He had not bungled his work, and it had been done. But as he looked down now, the muscles of his face quivered. And now he spoke the first word that had passed his lips since he had left the Flying W ranchhouse: "I reckon you've got what's been comin' to you!" He got down, unfastened the rope, deliberately re-coiled it and looped it around the saddle horn. Then he mounted and rode away. Grim, indistinct, fading into the blackness of the desert night, he went, half a mile, perhaps. And then, halting the pony, he turned in the saddle and looked back, his head bent in a listening attitude. To his ears came the sharp bark of a coyote, very near. It was answered, faintly, from the vast, yawning distance, by another. Catherson stiffened, and lines of remorse came into his face. "Hell!" he exclaimed gruffly.