This is the best adaptation of Eugene Sue's mammoth novel ,much better than the one by André Hunnebelle in 1962 with Jean Marais,and the miniseries French TV made in 1980.The scenarists achieved a real tour de force by making a ninety- minute movie from a 1,000 pages or more endless novel,while using a lot of characters featured in Sue's work:the hero , Rodolphe , a noble ,the grand duke of Gerolstein,in search of his lost child ,in the dregs of society,disguised as a plebeian (Marcel Herrand,one of Marcel Carné's favorite thespians who had just made "les visiteurs du soir" and was to make "les enfants du paradis" (The part of Lacenaire) just after "les mystères de Paris";a gallery of sinister-looking people ,all played by excellent actors ,particularly "la Chouette" portrayed by a terrifying Germaine Kerjean .Concierge Pipelet is also featured.The main problem is that things move very fast,and the plot may seem confused if you are not familiar with the novel -which is an exponential melodrama,with so many unexpected twists it 's just a joy-. Writer Sue was a socialist and his book was a plea against prostitution ,poverty,death penalty (and the idea he suggests in replacement of the guillotine makes hair stand on end :with a little surgery,make the criminal a blind man!).In the movie,the script keeps this "theory" as Rodolphe applies his punishment to the villain "le maître d'école" .The gloomy Gothic ending of the novel was suppressed -in the 1980 miniseries ,the scenarists would see it through- to secure a happy end ,which the audience did need ,during the dark time of the Occupation.