Christopher Nolan made his brother Jonathan watch Fritz Lang's The Testament of Dr. Mabuse — a 1933 German thriller in which a criminal mastermind orchestrates chaos from inside an asylum — to understand what the Joker needed to be: not a man who wants things, but a force of entropy who only wants to watch the system collapse. Lang made this film as the Nazis were rising. The Joker's speech about plans is Mabuse.
Films That Influenced The Dark Knight
