Escaped political prisoner Cesare Angelotti dashes into the church of Sant'Andrea della Valle to hide in the Attavanti family chapel.  As he hides, a grumbling old Sacristan shuffles in to clean up the chapel and pray.  Soon after, Mario Cavaradossi interrupts the old man as he enters to work on a portrait of Mary Magdalene that is inspired by Angelotti’s sister.  Mario takes out a portrait of Floria Tosca, the black-haired woman he loves, and compares it with the blonde Magdalene.  The Sacristan comments on the painting and leaves.  Angelotti comes out of hiding to greet his friend Mario, who feeds him and quickly hides him in the chapel again, as they hear Tosca’s voice as she approaches.

 

Always suspicious, the jealous Tosca questions Mario and reminds him to meet her that evening at his villa.  Recognizing the likeness of Angelotti’s sister in Mario’s painting, Tosca bursts with new suspicion.  He reassures her that he loves only her.  Once she has gone, Mario retrieves Angelotti from the chapel and they plan to hide him in a secret chamber in a well at Mario’s villa.  A cannon is heard signaling that the police have discovered an escapee and the two men run to the villa. 

 

The Sacristan returns with joyful choirboys who are preparing to sing a “Te Deum” later that day for the anticipated victory over Napoleon.  Their celebration is hushed by the entrance of the chief of secret police, Baron Scarpia, who is hunting Angelotti.  He finds evidence that Angelotti has been in the church and pieces together the events.  Tosca returns looking for Mario, and Scarpia takes advantage of the opportunity to vex her by planting thoughts that Mario is unfaithful.  As he shows her random evidence, he plans to seduce her.  Fearing Mario is untrue, she vows vengeance on him and leaves for his villa, believing she will catch him with another woman.  Police Chief Scarpia dispatches men led by his spy Spoletta to follow her.

 

In the Farnese Palace, Scarpia is filled with sadistic pleasure as he waits for the return of the men ordered to follow Tosca.  Still in search of Angelotti, the spy Spoletta arrives with Mario, who is interrogated and arrested for having aided the escape of a fugitive.  Tosca is heard singing at a royal gala downstairs.  After her performance, she enters to be questioned while Mario is being taken to a nearby room to be tortured.  Intimidated by Scarpia’s questioning and frightened by the sound of Mario’s screaming, Tosca reveals Angelotti’s hide out. 

 

Mario is brought in and collapses when he learns Tosca revealed their secret.  The officer Sciarrone comes in to announce that Napoleon has won the Battle of Marengo, which is a defeat for Scarpia.  Mario rises up, and in defiance, gives a triumphant shout.  Scarpia has Mario dragged off to prison to await execution.  Tosca offers to pay Scarpia money for her lover’s release, but Scarpia will accept only her as payment.  He wants her to belong to him.  Desperate, Tosca accepts Scarpia’s cruel proposal as Spoletta enters to declare that Angelotti has killed himself rather than be captured.  Scarpia explains to Tosca that he will arrange a mock execution for Mario, but in actuality he instructs Spoletta to have the soldiers shoot him.  Scarpia draws up a document of safe-conduct for the lovers to leave the country, and he advances to embrace her.  Tosca stabs him with a knife and kills him.  She takes the document from his hands, puts a candle at his head, a crucifix on his chest and leaves.

 

 

As the church bells toll dawn, the voice of a Shepherd boy is heard.  Mario prepares for execution on the roof of the Castel Sant'Angelo.  He has written a farewell note to Tosca and bribes the jailer to give it to her.  Mario is overcome with his memories of love with Tosca and begins to despair.  Suddenly Tosca rushes in to tell Mario that she has killed Scarpia.  She shows Mario the document and explains that the execution is a setup.  Tosca advises him to go along with the plan and fake his death when the firing squad shoots.  They express renewed hope and excitement for their future.  The soldiers fire and leave.  Tosca encourages Mario to get up, but when he fails to move, she realizes that Scarpia’s wickedness has transcended the grave.  Spoletta arrives to arrest Tosca for Scarpia’s murder, but she cries to Scarpia to meet her before God, and leaps to her death.