'M' was the first sound film directed by Fritz Lang, the German expressionist famed for films such as 'Metropolis', the Dr. Mabuse series, 'The Big Heat' and indeed 'M', which he regarded as his finest. The story goes like this - the city is being terrorised by a child-murderer (Peter Lorre), after he claims another victim the police step up their efforts to track him down. However the increased police presence on the streets annoys the criminal underworld who also try to track the murderer down in order to get the police presence to subside.

The use of sound, in what was Lang's first sound film, is very impressive. This film contains the first example of a leitmotif, associating Grieg's "In the Hall of the Mountain King" with Hans Beckert, the child-murderer. Lorre's performance as Beckert (supposedly an amalgamation of real-life German serial killers) is exceptional and without a doubt the greatest of his career. The film wouldn't be the visual spectacle it is without Lorre and his vast range of facial expressions.

'M' is Lang's most innovative and influential film. The use of shadows and light, questions about morality and the unsavoury subject matter all help to make this film the precursor to film noir. Lang's directing is impeccable, from the use of sound as I outlined earlier to foreshadowing and suspense of almost Hitchcockian levels.

On my first viewing there was one scene that bothered me - the slightly anticlimactic ending. Whilst not giving anything away I will say that Beckert gives a desperate monologue that attempts what would later become a staple of film noir - to make us understand why the character did what they did. Supposedly the monologue is also an allegory that shows Lang's feelings towards the justice system in Germany at the time but my preferred interpretation is that of Lang questioning the use of capital punishment (that was used on the "Vampire of Dusseldorf", one of the inspirations for Beckert, a few years earlier). Beckert's fate is deliberately ambiguous but it is hinted that capital punishment was used.

The final shot is that of the victims' mothers with one of the mothers saying, "This will not bring our children back" and the mother of the latest victim saying "One has to keep a closer watch over the children. All of you." This is Lang trying to say that the serial killings of children (likely those committed by the "Vampire of Dusseldorf") were preventable and while that may be a noble message to try and get parents to keep a closer watch over the children it seems tacked on at the end and to me comes across as propaganda.

While I may not be raving about the ending I give this film a high recommendation.