Rome, June 17, 1800, The Church Sant’Andrea della Valle
Angelotti, a Consul of the former Republic of Rome, has fled the prison inside the castle Sant’Angelo, where he had been held captive since the royal Neapolitan troops destroyed the Roman republic. He takes refuge for the moment in the chapel of his sister, the Marchesa Attavanti. In the church, Mario Cavaradossi is painting a picture of Maria Magdalena. The suspicious sacristan observes the painter, and secretly reviles him as a heretic and dog of a Voltairean. When Cavaradossi is alone, Angelotti comes out of the chapel. The painter, familiar with the former Consul’s fate, immediately declares his willingness to help the escapee. But Angelotti has to hide again when Floria Tosca, the famous singer and the painter’s beloved, wants to enter the church. Her jealousy is aroused when she notes the similarity between Cavaradossi’s painting of Maria Magdalena and Attavanti, whom the painter has portrayed while at prayer in the church. After Tosca leaves, cannon shots signal that Angelotti’s escape has been discovered. Cavaradossi and the fugitive Angelotti leave the church together, with the plan of hiding the Consul at the painter’s country home.
When the news reaches Rome that General Melas and his Austrian troops have defeated Napoleon Bonaparte and the French army at Marengo, a »Te deum« is prepared to celebrate the event. Scarpia, the feared police chief, suddenly appears at the revels of the chapel choir. Circumstantial evidence leads him to the conclusion that Angelotti was in the church and that the painter Cavaradossi – whom the secret police have long suspected is a freethinker – has assisted the Consul’s escape. With the aid of Attavanti’s fan, found by one of his henchman, Scarpia reawakens the jealousy of Tosca, who has returned to the church. A livid Tosca hurries to Cavaradossi’s country house, until now unknown to the police. Scarpia orders his agents to follow her.
The Police Chief‘s Room in the Palazzo Farnese
Scarpia waits for his underlings to return with captives: the fugitive Angelotti and Cavaradossi. He wants to blackmail Tosca into alquiescing to his sexual desires. Spoletta appears to report that he could not find Angelotti, but has arrested Cavaradossi. When the painter is brought forward, Tosca’s voice is heard from the nearby Hall of the Queen, singing a cantata on the occasion of the Austrian victory. Cavaradossi denies any hand in Angelotti’s escape. He is taken away for interrogation, where torture is planned to force him to confess. While Mario’s screams of pain are heard, Scarpia subjects Tosca to a terrible psychological terror. To rescue her beloved, she reveals Angelotti’s hiding place. Cavaradossi, released from the torture, hears the fresh news that Bonaparte, not Melas, has won at Marengo; he is unable to conceal his jubilation. Scarpia orders his execution. Only if Tosca gives herself to Scarpia will he spare Cavaradossi’s life. Faced with her lover’s imminent death on the gallows, Tosca indicates her willingness to submit. Scarpia assures her that Cavaradossi will not be hanged, but shot the next morning – but only as a ruse! He gives her a pass and claims it will allow her and Cavaradossi to flee. But when he approaches Tosca, she stabs him to death.
Inside Castle Sant’Angelo. Early morning
Before his execution, Cavaradossi is put in the custody of a guard. His thoughts return to happy hours with Tosca, who then appears and reports what has happened. Cavaradossi is unable to share her joy in the coming liberation, since he understands Scarpia’s methods better than she does. He has a feeling the promised fake execution is only a trick. But Tosca regards the execution as a kind of theater performance, and gives her beloved tips on how to fall convincingly. The firing squad lines up and carries out the execution. Only now, confronted with Cavaradossi’s death, does Tosca realize that Scarpia has deceived her. Meanwhile, the corpse of the police chief has been discovered. Tosca eludes her pursuers’ grasp by leaping from the battlements of the castle Sant’Angelo.