The central twist of "Unforgiven" is the complete transformation of its protagonist, William Munny. For the majority of the film, he is portrayed as an aging, regretful man who is physically inept and struggles with the ghost of his past. He can barely shoot a tin can and falls off his horse. The audience is led to believe his journey is about a final, reluctant act of violence before returning to his peaceful life. However, the true climax is a subversion of this expectation. After Sheriff Little Bill Daggett tortures and kills Munny's friend, Ned Logan, and displays his body outside the saloon, Munny is pushed past his breaking point.
He takes a drink of whiskey for the first time in over ten years, an act his wife had cured him of. This drink symbolizes the death of his reformed self and the resurrection of the cold-blooded killer he once was. He rides into Big Whiskey during a storm, walks into the saloon, and calmly executes the unarmed proprietor. He then methodically slaughters Little Bill and several of his deputies in a swift, brutal shootout. The hidden meaning is that Munny's reformation was fragile, contingent on the peace his wife brought him. Without that influence, and provoked by sufficient injustice, his true, violent nature re-emerges, more terrifying than any of the legends told about him. The film's ultimate revelation is that the monster was not dead, merely sleeping, and that the violence of the West is a corrupting force from which no one truly escapes.