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.