Opera in two acts by Ludwig van Beethoven
Leonore has assumed the name of Fidelio to penetrate into the prison where Florestan, her husband, is kept prisoner. She manages to be employed as a prison warder.
Marzelline, the daughter of Rocco, the prison master, refuses Jaquino's proposal of marriage. She loves Fidelio. By her betrothal to Marzelline, Leonore hopes to get Rocco's help for penetrating into the underground sections. Rocco on his turn hopes for relieving his conscience by making Fidelio an accessory. Pizarro, the governor, gets a warning that a surprising inspection is planned by the minister. He decides to put to death Florestan, his political adversary and only unlawful prisoner. He needs Rocco's help to execute this plan. Leonore asks Rocco to release the prisoners from the lighter prisons where she supposes her husband. Rocco gives permission to do so. — As Pizarro gets to hear about it, he orders all prisoners to be immediately locked again.
After two years of solitary confinement, Florestan's resistance threatens to break down. Rocco and Leonore open the cistern which is planned to be the grave for the secret prisoner. Leonore is ready and willing to save the stranger. She recognizes him to be her husband. As Pizarro tries to eliminate his adversary, she prevents this murder. As the minister's arrival is announced, Pizarro has to welcome him. Leonore and Florestan are together again without knowing their fate. Don Fernando, the minister, orders all prisoners to be brought before him and issues a general amnesty. Rocco accuses Pizarro of attempted murder. Pizarro has to resign. The minister takes up the appeal made by the people in declaring it his original intention.