Act I

Political fugitive Cesare Angelotti, a former Consul of the Roman Republic, is hiding in Sant'Andrea della Valle basilica, having escaped from prison. His sister, the Marchesa Attavanti, has prepared women’s clothes for him so that he can leave Rome unrecognised.

The Sacristan appears. He is unhappy with his job and with Mario Cavaradossi, the artist who is painting the church. The artist himself enters. The Sacristan recognises a beautiful parishioner in the painted image of Mary Magdalene, and Cavaradossi reflects on how different beauty can be. Grumbling, the Sacristan leaves, and Angelotti draws Cavaradossi’s attention. The artist is ready to help the fugitive, but Floria Tosca, a famous singer, comes in at this moment, and Angelotti hides again, taking Cavaradossi’s lunch basket with him.