Netflix it: Les Enfants Terribles (1950)

The best French film of the 1950s.

From Criterion:

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This legendary collaboration between resistant Melville and collabo Cocteau, who also wrote the screenplay and provided the narration, seems neither to have been a grudge match nor a picnic. Cocteau admired Le silence de la mer and approached Melville about filming his novel. Cocteau’s choice of Melville may have been influenced by the writer’s desire to turn his latest flame, Edouard Dermithe, into a movie star (an endeavor likelier to succeed if Dermithe worked with a director besides Cocteau himself). On Melville's part, it would seem odd to follow one thanklessly adapted famous novel with the adaptation of another famous novel, but he genuinely liked the story, and it was a project that was sure to draw money (which was desperately scarce at the time). As Melville probably anticipated, critics endlessly parsed the finished film to decide what belonged to Cocteau and what came from him.

Melville later said he had been "flattered" to be chosen by Cocteau, adding that he "quickly got sucked into it." Cocteau wanted far more control than Melville would give him. When the author tried to change his own script, Melville told him that if he planned to write a new Les enfants terribles, he wasn’t interested in filming it. Melville gave way on two points that he regretted: the casting of Dermithe as Paul and the "updating" of the action from 1929 to 1950. When Cocteau "inadvertently" called "cut" in the middle of a scene, Melville had him thrown off the set. In Melville on Melville, the director acerbically speculates that Cocteau hoped Melville would die during shooting, so Cocteau could simply take over the film. In the end, Cocteau's screenplay turned out to be an almost literal transcription of his book. Melville's transposition is architectural, musical (and to some extent a matter of casting)--like Le silence de la mer, a masterful, poetic rendering of words into images.
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