Purchasing the Carney Carnival and Road Show, unscrupulous sportsman Martin Trask assumes he has ownership of Rex, the world's greatest trained horse, and its rider, Margie Smith , but the girl releases Rex, flees from Trask in a runaway wagon, and finds shelter with young cowboy farmer Jack Merritt, with whom she falls in love. Trask cancels the mortgage he holds on Jack's property in return for Margie's accompanying him, but Jack learns the truth and pursues them. Rex comes to Margie's aid and kills Trask, while Jack rescues the girl from a tree limb on the side of a cliff.