In Rooster Cogburn, Eula Goodnight is a strong and determined woman who seeks revenge for the death of her father, Minister Goodnight, and the brutal assault on the women in her town. Despite being warned of the danger, she sets out on horseback to find Marshal Rooster Cogburn, a legendary lawman known for his unrefined ways and sharpshooting skills.
Cogburn initially refuses to help Eula, but eventually agrees to track down the gang of outlaws who committed the heinous crime. The two set out on a dangerous journey across the rugged frontier, encountering various obstacles and facing off against the gang members along the way.
As they travel together, Eula and Cogburn develop a mutual respect and admiration for each other, despite their differences in personality and background. They also confront their own personal demons, including Cogburn's struggles with alcoholism and Eula's guilt over her father's death.
The climax of the film features a dramatic shootout between the lawmen and the outlaws, culminating in an epic showdown between Cogburn and their leader, Breed. In the end, justice is served and Eula finds closure for her father's death, while Cogburn is offered redemption for his past mistakes.