The Joker is the main antagonist of the 2008 superhero film The Dark Knight, the second installment of Christopher Nolan's The Dark Knight Trilogy. He was a psychotic anarchist and notorious criminal mastermind who, describing himself as an agent of chaos, rose to power in the criminal underworld by thrusting Gotham City into turmoil, and drew Batman ever closer to crossing the fine line between heroism and vigilantism.