With America slipping inexorably towards civil war, Captain Whitlock (Robert Sterling) has assumed command of a New Mexico army post, situated near to a tribe on Navajo Indians. His second in charge, Lieut. Sayre (Audie Murphy) is a childhood friend of Navajo Chief Menguito and has maintained peaceful relations in the area...until now. Duped by warmongering Confederate sympathisers intent on provoking the Navajos, Lieut. Sayre now finds himself fighting his once close friend. He must uncover the truth and expose those responsible for the charade before Meguito's braves collide with the U.S. Cavalry in all-out war.