Marguerite de la nuit (1956)

In Paris, after an evening at the opera, the old, stuffy Dr. Faust is approached by a certain Mr. Léon, an enigmatic, elegant man who, a little earlier, had been dealing drugs to opera singers. Mr. Léon offers him a cigarette, and although he never smokes, Faust accepts it and is astonished to discover that it burns without being consumed. As if under a spell, Faust follows the strange man to the Pigall's cabaret, where once again he breaks with his habits by drinking the alcohol Mr. Léon offers him. At the cabaret, the old doctor is dazzled by Marguerite, a seductive dancer who has come up from the gutter. He bitterly regrets his ascetic life and his lost youth. That is all it takes for Mephisto to drop his disguise and offer him his twenty-year-old self again in exchange for a pact signed in his blood. The next day, the young Dr. Georges Faust rushes to Pigall's to see Marguerite again. A romance blossoms, but when Marguerite's former boyfriend intervenes, Faust kills him in the ensuing fight. The lovers take refuge with Marguerite's brother, a priest. After learning of the pact and discussing it with her brother, Marguerite meets Mephisto to buy back Faust's soul. Mephisto knows only one kind of bargain: one soul in exchange for another. Marguerite then signs her own damnation to free her lover. On the train that is to carry Marguerite into eternal darkness, Mephisto releases her from the pact, because she has risen spiritually, while Faust is condemned to spend the rest of his days in the hell of his mediocrity.