The movie The Dark Knight explores themes of crime, justice, and corruption. Bruce Wayne/Batman takes on the role of vigilante hero to fight criminals like the Joker, who seeks to challenge societal notions of justice. Harvey Dent is initially seen as a symbol of hope in the criminal justice system but becomes corrupted and turns into the villain Two-Face with the help of the Joker. The film examines how even seemingly innocent people can become corrupted and how far heroes and criminals will go in their conflict.