"Duel in the Sun" is a melodramatic treatment of a Western theme concerning a conflict between two generations of the McCanles family. The elderly and crippled McCanles Lionel Barrymore presides with an iron fist over his a vast cattle estate with his invalid wife Laura Belle Candles Lillian Gish. Their two sons, Lewt and Jess, are polar opposites: the educated Jess “the good son” Joseph Cotten takes after his refined mother, while Lewt "the bad son" Gregory Peck emulates his domineering cattle baron father. The adoption of the young orphan girl Pearl Chavez, the "half-breed" offspring of a European gentleman and a native-American mother, whom Pearl's father has murdered and been executed for his crime, introduces a fatal element into the McCanles family. The "film noir" ending includes an attempted fratricide and a suicide-like love pact, destroying the McCanles family.