Sinister, dark and foreboding, Fritz Lang's M tells the story of Hans Beckert (Peter Lorre), child molester and murderer. Gangsters, beggars and petty criminals, incensed by both the crimes and the police crackdown, track the killer themselves. Cornered, caught and dragged off to face an equally barbaric form of justice, Beckert endures his own personal torment. Allegedly based on the story of Peter Kürten, the "Monster of Dusseldorf", M remains one of the most chilling serial-killer films ever produced.