La Beaute du Diable aka Beauty and the Devil (Rene Clair, 1950)

After fifty years of service to the University and science without enjoying the pleasures of life, Professor Henri Faust is visited by the servant of Lucifer, Mephistopheles, who offers youth and a new life to him. Professor Faust switches body with Mephistopheles and the young Henri meets the gypsy girl Marguerite, but he is accused of killing Professor Faust and is arrested. Mephistopheles tries to force Henri to sign a contract to give his soul to Lucifer. Henri refuses and Mephistopheles schemes an evil plot, bringing Henri to the court to become successful, transforming sand into gold and becoming the lover of the Princess. When Henri is dumped to the poverty again, he is lured by Mephistopheles and accepts to sign the contract. Will Lucifer win the battle against the integrity of Henri and the love of Marguerite with him?