Married Count René is in Paris for Carnival, at an inn with his friend, the poet Josef. When René picks up an attractive girl, she is revealed to be Madame Pompadour, and he is placed under arrest. She gains him a reprieve, but she demands that he serve as her personal bodyguard and that Josef write a birthday play. She tells René to keep his distance - until midnight. Meanwhile, René's wife arrives, in search of her missing husband, and Louis XV wants to catch his mistress together with her lover. But clever Madame Pompadour is able to avoid detection, as she presents René's wife as her sister.