John Philip Clum (Audie Murphy) is an Indian agent sent to the San Carlos Apache reservation in Arizona in 1874 to prevent further bloodshed and stop the renegade chief, Geronimo (Jay Silverheels), from encouraging young Indian braves to take up their weapons and fight once more. Clum's struggle is made worse by the townsfolk and cavalry who believe that the only good Indian is a scalped one.

But whilst Clum makes enemies of the governor, cavalry officers and the more headstrong Apache braves, he begins to win the trust of the elders by talking of the government's new peace plan for Indian autonomy rather than submission. Tianay (Ann Bancroft) is the beautiful Indian widow who cleans house for Clum and gradually falls in love with him. But when Clum brings his young fiancee (Pat Crowley) from back east to marry him and the young Apaches think that Tianay should keep to her own race, the spark of an uprising is lit and Clum must put his life on the line to prevent the reservation from siding with Geronimo.