Fritz Lang's 'M' (1931) is an undisputed classic of world cinema. Lang considered it his most lasting work. Peter Lorre's extraordinary performance as the childlike misfit Hans Beckert was one of the most striking of film debuts, and it made him an international star. Lang's vision of a city gripped with fear, haunted by surveillance and total mobillization, is still remarkably powerful today. And 'M' resonates too in the serial-killer genre which...