La bestia humana

The point that you really could do with reading at least some of Zola's mammoth saga is well taken - I've only read Germinal so I'm afraid that lets me out. The many puzzling bits in the plot would probably not be: why such fleeting references to ancestral drunkeness and epilepsy, what happened to Cabuche, were Jacques and Bess in a serious sexual relationship?

Basically outraged and cuckolded middle-aged husband murders beautiful young wife's childhood ancient sugar daddy, she (Simon) drifts into stocky Gabin's and/or a lithe young man's arms, sex and violence result as surely as the earthy pre-War French trains ran on time. Some marvellously atmospheric nitrate b&w photography even when under the arc-lights, some scintillating and also some surprisingly clumsy framings from Renoir, some tremendous acting from the leads and trains, some brief but jarring full orchestral incidental music, and what are we left with all these decades later? A clever, well-made, entertaining and then-popular now relatively ignored (IMDB eg Bete Humaine 17 Amelie 1033) film applauded to the rafters as Art because it's Renoir. There could be no other outcome for this film - it was Fated to be Art after all!

It's very good and been one of my favourites for decades now, not as essential mind furniture but more as an enjoyably engrossing proto-noir romp with subtitles.