The movie follows Clyde Shelton (Gerard Butler), a model citizen turned vigilante after his family is brutally murdered by an ex-judge, Nick Cheevers (Jamie Foxx), who is convicted and later paroled. Disillusioned by the legal system, Clyde meticulously plans a campaign of revenge against every person connected to the killer's acquittal, including corrupt cops, lawyers, and the judge himself. The narrative shifts between the legal proceedings of the original crime and Clyde's methodical retribution, culminating in a morally complex climax.