In his boss’s absence Frosch the jailer has drunk more than he can cope with. Even Frank is not absolutely sober on his return from the ball and wants to rest at his writing-desk. But the prison comes to life, all the acting persons turn up one after the other. At first Adele, who looks for a sponsor of her artistic talent, then Eisenstein who is amazed to realise that he has already been in prison for a night. When Rosalinde appears with the arrested Alfred and demands an interview with a notary, the disguised Eisenstein takes up this part and gets to know about the events of the previous night. Eisenstein is finally persuaded that all this was part of Dr.Falke’s revenge. All is well that ends well: "the Bat’s revenge" started the amusing game and the only to blame is - the champagne.