ACT I

Angelotti, who has just escaped from prison, finds a key left for him in a church by his sister, the Marchesa Attavanti, and hides in the Attavanti chapel. The sacristan enters, grumbling about having to clean the painter Cavaradossi’s brushes. Cavaradossi returns to his work and, when Angelotti emerges from hiding, promises to help him but tells him to hide again when they hear Tosca approaching. AIthough she begins to suspect that he is having an affair with the Marchesa, Cavaradossi reassures her of his love before she leaves.

Angelotti tells Cavaradossi that his sister has left him some female clothing and that he intends to escape in disguise. Cavaradossi mentions a hiding-place down the well in his garden in case of emergency. They hear a shot, indicating that the escape has been discovered, and Cavaradossi rushes Angelotti to his safe house.

The sacristan announces a grand Te Deum to celebrate a report of a victory for the current regime. Excitement at this news is cut short by the arrival of Scarpia, on Angelotti’s track. A search of the church reveals a fan with the crest of the Attavanti and, when Tosca returns, looking for Cavaradossi, Scarpia uses it to inflame her jealousy, as a way of winning Tosca for himself.

ACT II

Scarpia waits for Tosca, who is singing at an official reception to celebrate the victory. Spoletta informs him that Angelotti has still not been found but that Cavaradossi has been arrested. Under interrogation he denies any knowledge of Angelotti. Tosca arrives as Cavaradossi is led off to torture. At first she refuses to tell Scarpia anything, but finally she can bear Cavaradossi’s suffering no longer and reveals Angelotti’s hiding-place. When Cavaradossi is brought in and hears Scarpia ordering the arrest of Angelotti it is obvious that Tosca has betrayed him. At this moment the news of a serious defeat for the current regime arrives. Cavaradossi is triumphant and Scarpia orders his execution.

Tosca begs for the life of her lover and Scarpia names his price: she must have sex with him in exchange for Cavaradossi’s freedom. Seeing no alternative, she agrees, and Scarpia orders Spoletta to perform a mock execution of Cavaradossi, after which he and Tosca will be able to escape. As he claims his reward, however, Tosca kills him.

ACT III

Cavaradossi awaits execution. He remembers the happiness Tosca had brought him. Tosca then tells him what has happened and prepares him for the mock execution. She realises too late that she has been deceived by Scarpia: the execution was real. Tosca pays for Scarpia’s murder with her own life.