At the age of seventeen, Ace Donovan witnessed the hanging of his father and brother by six contractors hired by the railroad to run people off its lands. He has spent the past fifteen years tracking down these men and exacting his own form of justice. Only one of the six remains. Dulcie Slaughter, widowed less than five months after her wedding, hires Donovan to trail her cattle to market. He knows it's taboo to bring a woman on a cattle drive. Therefore, when she insists on joining the drive, Donovan decides against the thousand-mile trip to Kansas, but instead trails the cattle over the Superstition Mountains to Fort Apache, Arizona. The Apache believe the Screaming Woman spirit is angry because they didn't prevent the white man from invading sacred lands. Outlaws use this Apache legend in an attempt to steal the herd. Dulcie's trust in Donovan is shattered when one of the outlaws recognizes him as the man who killed her husband.