The Dark Knight, Christopher Nolan's 2008 sequel to Batman Begins starring Christian Bale and Heath Ledger as the Joker. TDK is loosly based on the 1996 series The Long Halloween, which retold Two-Face's origin. It's the 2nd film to earn more than $500 million at the North American box office, and is the fifth highest grossing film worldwide. described his Joker as a "psychopathic, mass murdering, schizophrenic clown with zero empathy". To prepare for the role, Ledger lived alone in a hotel room for a month, formulating the character's posture, voice, and personality.