The cinematographic career of Fritz Lang starts in 1916, the date in which he begins his work as script writer for the movie Die Peitsche, and develops until 1960 when after returning to Germany following a long exile in the US cinema, he shoots Die 1000 Augen des Dr. Mabuse, his final title in a fruitful career as film director along which he linked the topics and styles he favored since his early years in silent cinema. When in 1931, after many difficulties, he managed to get rolling the shooting of M, his first sound film, three years had already passed since he premiered Frau im Mond, his last silent film. By that time, Lang was already the most important director of the German cinema, with the only competition of the great Friedrich Wilhelm Murnau, thanks to the exceptional reception of his movies Der Müde Tod, Dr. Mabuse, der Spieler, Die Nibelungen and Metropolis.
M was not only his return, but also his consecration as one of the most powerful narrators of the new sound cinema during its first steps in Europe, and this was thanks to his use of the new sound techniques, which he integrated into the narration with much inspiration in order to describe the complex character Franz Becker, and to create the atmospheres, the two main elements that sum up the essence of one of the best films in history. Lang hired a young actor who was starting to shine in the theatre scenarios but had no previous movie experience to play the main character. Peter Lorre would debut in movies with this fearsome, and at the same time pathetic, killer of girls and would obtain a success he would later consolidate through a long and varied repertoire. After several films in German studios, he would be claimed from London in 1934 to work with Alfred Hitchcock playing the English version of The Man Who Knew Too Much and he would never return to Hitler's Germany. His debut in Hollywood was with Mad Love, a movie of his compatriot Karl Freund, and immediately after would play Raskolnikov in the great movie adaptation of Crime and Punishment by Josef von Sternberg. In the decade of the 30s his face became very popular thanks to the series of Fox movies on the oriental detective Mr. Moto, but it is his posterior works in key films of the time (The Maltese Falcon, Casablanca, The Mask of Dimitrios, Arsenic and Old Lace, 20,000 Leagues Under the Sea, Silk Stockings, The Patsy and his collaborations in terror films from Roger Corman in the 60s) what really provide proof of his capacity and versatility.
M is a script written by Lang with his then wife Thea von Harbou, and in collaboration with Paul Falkenberg, Adolf Jang and Karl Vosh, based on an original article by Egon Jacobson, whose first title was Killers are among us, but that had to be changed to avoid misunderstandings with the official interests of the emerging National Socialist Party, even though Thea von Harbou showed affinities with nazism. This would not prevent Lang from going on exile to Paris after his next movie Das Testament des Dr. Mabuse, and later moving on to the USA. Already in Hollywood, he would be the author of some of the most brilliant examples of the classical film noir period like Fury, You Only Live Once, The Woman in the Window, Scarlet Street, Clash by Night or While the City Sleeps; and also included some unusual forays into the Western genre like The Return of Frank James, Western Union or Rancho Notorious, but this is a different story.