The Criminal Genius of Fritz Lang

The Testament of Doctor Mabuse is an odd film. It's like one of those Shakespeare 'problem plays' or REAL LIFE where you're not quite sure of the genre.
So, first off it's a sequel to two early Fritz Lang films- Doctor Mabuse, the Gambler and M, the one a story of an evil criminal mastermind with a supernatural talent for mesmerism, the other a thriller following the hunt for a psychologically disturbed child killer. You can see immediately where the problem might be.

It's got suspense, big explosions, a couple of great action set pieces, redemption, comedy crooks, a grumpy copper who gets results, bizarre Edgar Allan Poe/Sir Arthur Conan Doyle era forensics where a typewriter clue is disregarded as worthless but there's a lot of messing around with messages on scratched glass and ballistics analysis is an astonishingly exact science.
Then there's an amazingly creepy scene with a man being possessed by a ghost (a ghost later seen to open doors in a manner which denies convenient psychological rationalisation).
It's basically got everything chucked in that you might fancy in an exciting ride, but it doesn't all quite hang together satisfactorily.

It's not helped that the villain's behaviour, hiding in the shadows transmitting messages to his underground network of hoods by radio, setting elaborate bomb traps with stupidly long countdowns and rigging his door knob to a recording of his voice saying “Go away!” have all been pinched by later far pulpier series and serials - King of the Rocket Men, that ghastly Demons episode last week and of course Doctor Who and Tanni in an exciting adventure with a Powerful Enemy.
The bomb bit is actually slightly stupider than the bit in Demons, if you can believe that, though it combines the rising waters and ticking timer threats far more interestingly and has the advantage of resolving its stupid fantasy peril in a sensible way.

What M and The Testament of Doctor Mabuse share beyond Lohmann, their endearing Police Commissar lead, is a sense of a country in which criminality flourishes and is highly organised- in an era of mass unemployment (when even Labour Exchange clerks are short on funds) it's suggested turning to crime is the only way out for some.
Real or imagined this powerful underground black economy seems to turn up time and again in the little German film and literature between the Wars I know. Certainly, the hyper-inflation of Weimar Germany appears to hang heavily on the film, a large part of Mabuse's plan to destabilise the State is built on circulating counterfeit money, he just has to spoil it all with artsy jewel thievery and mass poison gas attacks.
Top tip for any modern terrorists reading- destroying the banking system from within might just be more effective that some of that old fashioned bomb stuff. You probably know this and have been doing it for a while, of course.

Mabuse defeats himself in the end, which is handy because being essentially an idea, an idea that anyone might house, makes him rather hard to defeat otherwise. Quite why he chooses to give up, when all that's really gone wrong is that he's lost a few of his more rubbish henchmen isn't entirely clear, perhaps he's only really interested in destruction and doesn't really know what to follow his schemes up with, perhaps he's retreated to draw up fresh plans to replace those we see him tearing up at the end, perhaps his high profile but failed attack on the public will bring more anarchy than a successful attack would.
Lang was keen after fleeing Germany to say the film, suppressed by the Nazis, was a coded attack on Hitler, and yes it does feature an incarcerated mad man drawing up a plan for revenge on the world, which at a squint might be writing Mein Kampf in jail, and there is a moment at which Mabuse is reported to have said “I am the State!”, but it's a bit of a push.

Admittedly, coded attacks do have to be a bit obscure, but I suspect the film was genuinely banned for its exciting depiction of acts of terrorism against the State rather than for hinting the State and its violent opponents might be cut from similar cloth.