Rewarded for his heroism in the Civil War, Lt. John Dunbar (Costner), wants to see the American Frontier before it is gone. He is assigned to an abandoned fort where a Sioux tribe is his only neighbour. Overcoming the language barrier and their mutual fear and distrust, Dunbar and the proud Indians gradually become friends. Eventually, he falls in love with the beautiful Stands With A Fist (McDonnell), a white woman raised by the tribe. He learns the culture of the Sioux, lives with them, and even experiences the breathtaking excitement of a buffalo hunt, but his knowledge of the fate that will ultimately befall the tribe torments him. Finally, he is faced with a crucial decision that will cause him to examine his heart and soul before making a heroic choice that determines his destiny.