El secreto del capitán O'Hara (1966)

During the Civil War, Captain Richard O’Hara and his troop encounter Mary in the desert. Her convoy was attacked by Indians, and she was the only survivor. She was on her way to the fort, as she is engaged to Major Brush, its commander. O’Hara and Brush meet there; they have known each other since their time together at the military academy and have been at odds ever since. Among other things, Brush had O’Hara demoted by a court-martial for alleged cowardice and desertion. Mary falls in love with O’Hara. Another new couple at the fort, and an example of peaceful coexistence, are the scout Wills and a young Indian woman who works as a barmaid. Blinded by jealousy, revenge, and a desire to show off, Brush goes on the warpath against the Indian tribes. As a result, the fort is attacked by Navajos and Apaches and suffers heavy losses. After O’Hara’s courageous actions avert the worst, Brush recognizes his mistakes and asks the man he had wrongly demoted for forgiveness.