Scientist and professor Henri Faust (Michel Simon) is set to retire after decades of study, but he feels there is still much to discover. Enter Mephistopheles (Gérard Philipe), a minion of Lucifer, who offers to turn Faust into a young man. The scholar agrees, but now that he is young again, he finds himself distracted by women. Mephistopheles starts tempting him with more and more -- money, acclaim, even a princess (Simone Valere) -- in order to make Faust yield his eternal soul.