The tyrannical governor Don Pizarro has taken his enemy Florestan as a political prisoner, confining him to a secret dungeon. Don Pizarro spreads the rumor that Florestan is dead, but Florestan's faithful wife, Leonore, suspects the truth and sets out to rescue her husband. She dresses as a young man, calls herself Fidelio, and becomes an assistant for the jailer, Rocco, hoping to find a way to free her husband.
The jailer's daughter, Marzelline, becomes infatuated with Fidelio and plans to marry him, spurning her former sweetheart Jaquino. Rocco describes the prisoners in his care to Fidelio; the most unfortunate one of them all is in the deepest dungeon of the jail. Fidelio is convinced that this is her husband and tries to persuade Rocco that he needs her help caring for the prisoners, and he reluctantly agrees.
When Pizarro hears of an impending visit to the prison by his superior, Don Fernando, who suspects Pizarro of abusing his power, Pizarro decides to kill Florestan before he is discovered. Fidelio coaxes Rocco into allowing the prisoners outside for a moment. They file out of the dungeons fearfully, but rejoice in the feeling of fresh air. Fidelio fails to find her husband among the prisoners.
Rocco has agreed to let Fidelio help dig the grave in Florestan’ s cell and when the two enter, Fidelio can barely recognize her dying husband. Rocco allows her to offer the prisoner some wine and bread, which enables her to confirm that the man is indeed her husband. Florestan thanks her for her kindness, but does not recognize his wife in her disguise.
Don Pizarro enters, gloating over his prisoner. He draws a knife, but Fidelio rushes to shield Florestan, saying that Pizarro must first kill his wife. A trumpet announces the arrival of Don Fernando. Vowing yet to have his revenge, Don Pizarro rushes out of the dungeon, leaving Florestan and Leonore to reunite. Rocco returns with news that Don Fernando has a list of prisoners to be set free. Florestan is not on the list, but Rocco brings him outside with the others anyway.
Don Fernando is astonished to find his old friend Florestan among the prisoners. The sympathetic Rocco informs Don Fernando of Pizarro's misdeeds, whereupon Pizarro is arrested, Florestan is set free, and all pay tribute to Leonore whose courage and resolve have saved her husband.
Reprinted with permission from Opera Philadelphia