Hazel Clark, belle of the Diamond "S" Ranch, is fascinated by Cactus Jake, a bold, dashing, reckless cowboy. Good-natured Bill, another cowpuncher, is really in love with Hazel. Mary Donnelly, a very pretty and clever girl, who states that she comes from the east and is in search of health, becomes a guest at the ranch, whereupon Cactus Jake promptly forgets Hazel for the newcomer. Hazel is heartbroken and with the aid of her father, forms a plot for revenge. She announces that she is going away for a visit, but goes only to the next town where she obtains a false mustache and other disguises, and returns to the ranch where her father gives her employment as a gay and dashing young cowpuncher. She endeavors to win Mary away from Cactus Jake. One day her mustache falls off and her disguise is discovered. Bridget, a fearsome and redheaded, bony Irish woman, enters the camp at this time and corrals Cactus Jake, who is her recreant husband. Pretty Mary proves to be a female detective. Bill then wins the heart of Hazel.