The Murderer Lives at Number 21 is a 1942 film, the directing debut of Henri-George Clouzot, who co-wrote the script with Stanislas-Andre Steeman. I've mentioned Steeman before in relation to his very interesting novel Six Dead Men and the film imports from that book the detective Wens, played by Pierre Fresnay. It's a serial killer whodunit mystery with plenty of comic touches - a remarkable mix, given that the film was made during the German occupation of France.
We learn right away, in a pub scene, that a murderer who leaves the calling card of "Monsieur Durand" is terrorising the city. A vivid Hitchcock-style sequence sees a drunken tramp who has just won a lottery prize becoming the latest victim. Wens is under pressure to solve the mystery, and an aspiring musical comedy actress, played by Suzy Delair, also determines to make her name by finding out whodunit.
Wens is led to a boarding house - No. 21, Avenue Junot - where the murderer appears to live. The occupants are a motley crew, but although the killings continue, Wens finds himself confounded each time he seems close to identifying the culprit. The explanation for the puzzle, when finally revealed, is pleasingly quirky.
Hitchcock himself pointed out that filming a whodunit is very tricky, and Clouzot too would go on to find greater fame with stories that emphasised suspense rather than puzzle plots. But this is an enjoyable film to watch, a period piece that is lively and entertaining from start to finish. The fairly recent DVD version includes an insightful discussion by Ginette Vincendeau, which sets the film in its historical context. I'd like to know more about the collaboration between Clouzot and Steeman. Incidentally, in commenting on my post about Six Dead Men, Xavier Lechard recommended this film warmly. His praise of it was well merited.