In Scarpia's apartment above the Farnese Palace that evening, Scarpia sets his plan into motion and sends a note to Tosca asking her to join him for dinner. He then begins to craft a plan to kill Mario and have his way with Tosca. Scarpia, always suspicious of Mario, sends his men to follow Tosca.

Flying into another fit of jealousy, Tosca vows vengeance and rushes to Mario's villa to confront him with his lies. When Tosca enters the church again, Scarpia shows her a fan with the Attavanti family crest inscribed on it. The old sacristan is questioned, but the officers are unable to get their answers. It isn't long until the chief of the secret police, Scarpia, and his men rush into the church. The sacristan reenters the church followed by a group of choristers that are to sing a Te Deum later that day. The two men quickly flee to Mario's villa. Mid-explanation, cannons are heard in the distance signaling Angelotti's escape has been discovered. When she leaves the chapel, Angelotti reappears to tell Mario of his planned escape.

After a bit of explaining and consoling, Mario is able to calm Tosca down. She instantly recognizes the woman in Mario's painting as Marchesa Attavanti. It only takes one look of the painting to send Tosca into a fit of rage. She questions Mario about his faithfulness and love to her before reminding him of their planned rendezvous later that evening. Tosca is a jealous woman and she takes no effort to hide it. Mario happily greets him and gives him food and drink before quickly pushing him back into hiding as Tosca can be heard approaching the chapel. The two have been friends for quite some time and share similar political beliefs. The escaped prisoner, Angelotti, emerges from his hiding place to speak with Mario.

After the sacristan mutters disapproval of the painting, he leaves. As he paints, he takes a small statue of Floria Tosca, a singer and his lover, from his pocket to compare her beauty to that of his painting. Mario has never met Marchesa, but he has seen her about town. With blonde locks of hair, Mario's painting is based on Angelotti's sister, Marchesa Attavanti. Mario picks up where he left off the day before and resumes painting a picture of Mary Magdalene. After he finds a place to hide within the private Attavanti chapel, an old sacristan appears followed by the painter, Mario Cavaradossi. Inside the church of Sant'Andrea della Valle, an escaped Roman prisoner, Cesare Angelotti, bursts through the doors seeking refuge.

Tosca opera wikipedia