The opera opens on the Church of Sant’Andrea Della Valle where Cesare Angelotti, the former Consul of the Roman Republic, has escaped from prison. Angelotti hides in the private chapel of the church because his sister, Marchesa Attavanti, left a key for him at the feel of the Madonna statue. After Angelotti has hidden, the Sacristan begins cleaning the church. Mario Cavaradossi, a painter, arrives to continue his work on a painting of Mary Magdalene. The Sacristan comments that the painting could be a representation of a woman who has recently come to the church to pray every day (Angelotti’s sister). Cavaradossi sings of the contrast of this blonde Mary and his dark-haired love, Floria Tosca, the singer (Recondita armonia).
After the Sacristan has left, Angelotti comes out and greets his friend, Cavaradossi, and informs him that the Chief of Police, Scarpia, is searching for him after his escape from prison. Cavaradossi assures him that he will lend his help, when Tosca