Army of Shadows, and that was ten years ago. Melville did not make a lot of films, and almost all of them are available on some form of home video, so I hope to get to all of them this summer.
I'll start with Leon Morin, Priest, one of three films Melville made set during World War II. This one is in a small town in the Alps, where a woman (Emmanuelle Riva), widowed with two children, works in the office of a correspondence school. When the town is occupied by Italian troops (wearing ridiculously plumed hats) she hurriedly keeps her children safe by baptizing them.
Riva is an atheist and a communist, and on a lark, finds a Catholic church and picks out a priest to pick an argument with. She chooses Leon Morin (Jean-Paul Belmondo). When she starts her confession with "Religion is the opiate of the masses!" she doesn't get the expected response. He actually opens a dialogue with her. This will lead to several discussions in his flat, where he lends her books and they debate the existence of God, among other things.
Meanwhile, the threat of Nazi occupation looms, although this may be one of the least-scary occupying films I've seen. Early in the film, Riva's Jewish boss shaves his beard, dies his hair, and gets false papers to hie it of town. We hear of someone disappearing but most of the action is about the daily life on the town and Riva's growing attachment to Belmondo. Due to his good looks he becomes a confessor to many women in town, including a bottle-blonde who is determined to snare him. He calls her a birdbrain and she becomes devout.
The point of climax comes when Riva reveals her feelings for Belmondo. I won't go any further, but I will say the Legion of Decency did give the film their approval (this was 1961, and while the film does explore the topic of lesbianism, it isn't too radical).
Much of the film seems like a debate inside someone's head, but Melville was an atheist Jew, not a lapsed Catholic, as Riva is. In fact, he said the film was not about religion. Indeed, though a hefty chunk of the film is a dialogue between the two main characters, there is something else going on, perhaps it's one of those instances when everything but the main topic is addressed.
The film, in a Criterion edition, looks great. Melville employs almost every type of transition there is, mostly fading to black, though there are wipes. He does this even though he is cutting from one scene with Riva and Belmondo to another scene with the same two characters (which is a bit disconcerting).
Belmondo, who was a huge start after Breathless, went 180 degrees with Leon Morin, Priest. Melville took one of the biggest sex symbols in France and put him in a cassock. This seems par for the course for Melville's sense of humor.