Music by Johann Strauss, Jr.
Libretto by Carl Haffner and Richard Genée
Sung in English with projected titles
Approximate running time: 2 hours, 20 minutes, including one intermission
Vienna, between the world wars. The actress Rosalinde and her husband Eisenstein are in Vienna to celebrate the New Year. At the suggestion of their friend Dr. Falke, they are staying at the Imperial Hotel. Unbeknownst to both of them, Falke has hired the hotel concierge as part of his revenge plot on Eisenstein, two years in the making. Falke has even found an old lover of Rosalinde—an “unemployed” tenor named Alfred—to keep Rosalinde busy, along with a troupe of actors and dancers paid for by a bored Russian aristocrat, Prince Orlofsky.
Soon, Eisenstein is accused of cheating at the hotel casino in a rigged card game, and is ordered under house arrest. A lawyer, referred by Falke, makes the situation worse and doubles Eisenstein’s sentence. Falke urges Eisenstein to come with him to a costume party in the hotel ballroom hosted by Prince Orlofsky before going to jail, and Eisenstein secretly agrees.
Secretly, Falke has also sent Adele, Eisenstein’s chambermaid, an invitation to the party, leaving Rosalinde alone to Alfred’s embraces. Through artful misrecognition, Alfred is arrested in Eisenstein’s place just as a bellhop hands Rosalinde her invitation to the party.
The party is already in full swing as Falke promises Prince Orlofsky that he will not be bored tonight by his entertainment, “The Revenge of the Bat.”
Eisenstein arrives costumed as “Marquis Renard” and is immediately invited by Orlofsky to drink a round of vodka. Already a little tipsy, Eisenstein correctly mistakes Adele for his chambermaid, and the hotel concierge is announced as the “Chevalier Chagrin.” As the pièce de résistance, Rosalinde arrives disguised as a Hungarian countess.
Eisenstein immediately sets his designs on the “Hungarian” and uses his special pocket watch as a lure, promising that he will give it to her only if she reveals her identity. Rosalinde manages to steal the watch, and to prove that she really is a Hungarian countess, she sings the Csárdás, a Hungarian folk tune.
Prince Orlofsky asks Falke about his “Bat” story and Eisenstein overhears, boasting that two years before, after a similar costume party, he left a drunken Falke to sleep it off in a public square dressed as a bat—thus Falke’s nickname, Dr. Fledermaus, which is German for “bat.”
As the party disperses, Adele asks the "Chevalier" if he can help make her a star, and he asks her if she's got talent. Back in the lock-up, Alfred is still serving time in place of Eisenstein, and he requests a lawyer. Rosalinde finds Alfred there just as Eisenstein does a quick change with the lawyer, hoping to catch his wife in the act. As the pocket watch chimes, Rosalinde reveals herself as the Hungarian countess, Falke declares his revenge, champagne flows, and the party resumes to Orlofsky's laughter.
–Courtesy of Robin Guarino