Tom Reed's adaptation of the "Saturday Evening Post" story by Eli Colter finds Texas wrangler Tom Kilpatrick persuading the ranchers of the Pecos area, led by John Rambeau, to buy a Brahma bull on a cooperative basis to improve their depleted cattle strain. The bull escapes, due to the carelessness of Windy Lucas. The mishap is seen by Larch Keegan, young rancher in love with Cherry Lucas, Windy's adopted daughter. Larch, jealous of Tom as a rival for Cherry and for water rights, fixes the blame on the wrangler. The bull terrorizes the countryside, injuring farm women and killing other bulls. Larch and his brothers, Hoy and Happy, incite the ranchers to shoot the bull on sight, but Tom begs for time to capture it alive. Tom corners and lassos the bull in the hills, but his horse is no match for the bull, who escapes again. Tom then sets out to capture the Widow Maker, a famous wild horse, knowing the horse is the only one capable of holding the lassoed bull.