One of the most distinguished and technically accomplished early sound films, Fritz Lang's M (1931) revealed the expressive possibilities for combining sound and visuals, in a metaphorically loaded story about pre-Nazi Germany. Working from the true story of the Dusseldorf child murders, Lang matches a mother's anguished calls for her daughter with images of an empty stairwell and a lost balloon rather than show the killing, while the murderer's obsessive whistling becomes the calling card for his threatening presence. Beyond the use of sound, Lang takes a pessimistic view of German society, using editing to equate the police with the criminals, while Fritz Arno Wagner's fluid cinematography creates a gloomy night world of shadows and paranoid entrapment. Lang's documentary-like attention to the details of the search, combined with the absence of non-diegetic music, matches the stylization with an equally creepy element of realism. The killer may be sick, but the society pursuing him isn't that much better. A worldwide success and a star-maker for Peter Lorre, M influenced movies from those of Orson Welles to the American film noir of the 1940s; Lang himself left Nazi Germany for Hollywood in 1933. The 111-minute version features an added courtroom ending. The movie was remade by Joseph Losey in 1951 as an allegory of Cold War-era Communist "witch hunts."