Reporters Peter Drante and Conny roam Hamburg’s Reeperbahn at night, uncovering three intertwined tales: Lilli, a aging dancer, searches for her missing husband who once shot her in a jealous rage; multimillionaire Alexander Borgess faces blackmail over past indiscretions; and Karin Thorwaldt seeks Borgess’s aid to secure her fiancé’s acceptance by her conservative father.

Young Count Georg Wolkersheim is sent to the Congress of Vienna to represent the interests of his country, Reuss-Schleiz-Greiz. Tensions arise between the count, his wife Melanie, and their two chamberlains, and when the four attend a court ball, Melanie leaves Georg, assumes the identity of a famous actress, and attracts the affections of Crown Prince Ludwig of Bavaria.

Theater director Falke, dressed as a bat, ends up in prison after a merry carnival night. Director Frank only releases him after some time. Falke decides to take revenge on his friend Gabriel von Eisenstein, to whom he owes the whole affair. The annual masked ball at Prince Orlofsky's provides the opportunity. Falke stages a game of mistaken identity in which Eisenstein does not recognize his own wife and courts her, while maid Adele appears as the countess. Eisenstein is duped, Falke has taken his revenge.

A young actress in love ensnares the director she admires by successfully playing the role of his ideal woman—the homemaker.