James Collins leaves his dear old mother and goes West, where he becomes connected with the Bar Diamond Outfit. He finds the life of a cowboy arduous and the pay meager. The possibilities of owning a herd of his own by blotting brands or branding calves, occurs to him, as it has to many others, who desire quick results from very little effort. Six months later, he is a full-fledged cattle thief, branding cattle, under his own registered brand, while ostensibly an honest cowboy in the employ of the Bar Diamond Ranch. He writes his mother of his success and she, never dreaming of the hazardous occupation her son is following, plans to join him in the West. Jim grows reckless in his branding and starts blotting his employer's brand. It is soon noticed by the cowboys and they keep a sharp watch for the cattle thief. At last, the ranchman himself discovers the rustler branding cattle and riding over alone, he is surprised to find one of his own men engaged in the nefarious work. He bitterly rebukes him and Jim, drawing his gun, shoots his employer, and then attempts escape. The shot is heard by the cowboys and they come riding over to find their employer dead. They start after the rustler, and after a long chase they run him down and he is shot. Ed Neville, the foreman, finds a locket hanging around the rustler's neck and removes it, and the boys carry the body away. Soon a heap of dirt on the prairie marks a murderer's grave, and the cowboys put the last spade of dirt on the mound and hurry back to the bunkhouse. They are discussing the rustler's crime when a livery rig drives up to the bunkhouse, and a dear old white-haired lady alights and asks for James Collins, explaining that she is his mother. All the chivalry in their nature is aroused, and the boys determine that this innocent mother shall never know that her son died a criminal and a murderer. They take her into the bunkhouse, and then hurry away to the rustler's grave, and cover it with flowers. On their return Ed Neville gently informs her that her son had died an heroic death, and had begged that the locket he wore be returned to his dear mother. They escort her to the rustler's grave and there leave her, that she may be alone with her grief. As she has no ties in the east, the boys ask her to remain with them and be the mother of the ranch.