Exciting and eccentric big city crime story, steeped in smoke, mystery, and shadow world Expressionism. It’s Fritz Lang’s second masterpiece in a row, following 1931’s M, and one of the best-aged films of its era. Lang—a famously tyrannical perfectionist who insisted on real guns firing real bullets on the set without caring how unsafe his cast and crew felt—crafts a madman’s classic here that moves fast and shoots down cliches at every turn.
Like M, it’s about a criminal who confounds both the police and the underworld. Even the crooks who work for him don’t know who he is and can’t understand why he never takes a cut of the money they make. Meanwhile, all the police have is a tip that his identity is apparently notorious evil super-genius Dr. Mabuse. However, Mabuse has been locked up in an asylum for ten years and is in a catatonic state where all he does is stare into space and scribble notes so madly that his hand continues making writing motions even when they take away his pen and paper. So EVERYONE’S trying to figure out this one. 
It’s set ten years after Lang’s 1922 silent serial, Dr. Mabuse, der Spieler. See the original if you’re curious (I found it boring), but it’s not necessary to get a grip on this. In less than two minutes, Lang and co-writer Thea von Harbou sum up everything you need to know.
While the Nazis admired Lang’s previous films, they banned this one in Germany due to its perceived anti-government leanings (or as a translated Joseph Goebbels put it, “it proves that a group of men prepared to go to any lengths, if they really want to, is able to lift a state out of its hinges”). It didn’t even get a public screening there until 1951. Meanwhile it played the rest of the world in cuts that ranged from seventy-five minutes to 111 minutes long. It wasn’t until 1973 that audiences finally saw the definitive, restored 121-minute version.
This was Fritz Lang’s last German film. In 1934, he shot one film in France, Liliom, and then went on to a long career in the United States.