The sacristan enters with choirboys who are preparing to sing in a Te Deum celebrating the recent victory against Napoleon at the Battle of Marengo. A cannon signals that the police have discovered the escape, and he and Cavaradossi flee to the painter’s home.

When Tosca has left, Angelotti again comes out of hiding. Suddenly recognizing the Marchesa Attavanti in the painting, she accuses him of being unfaithful, but he assures her of his love. When he lets her into the church, she jealously asks Cavaradossi to whom he has been talking and reminds him of their rendezvous that evening. Cavaradossi recognizes him and promises help, then hurries him back into the chapel as the singer Floria Tosca, his lover, calls from outside. Angelotti, who was a member of the former Bonapartiste government, emerges from his hiding place. The painting has been inspired by Angelotti’s sister, the Marchesa Attavanti, whom Cavaradossi had seen praying in the church. Soon, the painter Mario Cavaradossi arrives to work on his portrait of Mary Magdalene. After finding the key his sister has hidden for him, he hides in his family’s private chapel. Rome, June 1800. Cesare Angelotti, an escaped political prisoner, rushes into the Church of Sant’Andrea della Valle.

How long is tosca opera