SYNOPSIS

Act One

    The plot sets in monarchic Italy, on June 1800. In the morning, Rome's church of Sant'Andrea della Valle is still closed for the believers. Cesare Angelotti, Consul of the fallen "Repubblica Romana", an escaped politi­cal prisoner, seeks refuge in the church. Here, in the Attavanti's Family Chapel, his sister Marquise (Marchesa) Attavanti, has hidden feminine clothes for him, so he could disguise himself and then escape from Rome, escaping from Baron Scarpia, the chief of the Roman police.
    In the church, an artist, Mario Caravadossi, con­tinues his work on a painting. The Sacristan (II Sagrestano) serves him. Caravadossi paints a picture of the sinner Maria Maddalena, but suddenly the Sacristan catches the likeness of Maddalena and Marquise Attavanti, which yesterday prayed in the church. Caravadossi sees emerged Angelotti. Mario tries to help the weakened fugitive, but the arrival of the famous Opera singer, prima donna Floria Tosca, who is in love with the painter, prevents him. She has come to the church to arrange with Mario about their meeting: today, after the evening performance he promises to meet her in their new villa.
    Caravadossi's inattention and his wish to be alone initially arouse Tosca's jealous suspicion. And when she also recognizes Marquise Attavanti in Maddalena's painting, her jealousy becomes a certainty in his faith­lessness. The artist calms her down. Eventually he has succeeded in making her go out.
    After that Carvadossi returns to Angelotti and pro­poses to hide him in a house, where the painter lives: there, in a case of a pursuit, he can hide himself in a well near the garden.
A cannon shot announces the discovery of Angelotti's escape, and Caravadossi with the fugitive go away through a secret passage.
Scarpia and his henchmen (sbirros) - Roman policemen, appear in the church. The criminal might hide himself only there. The sbirros search the church. Scarpia asks the Sacristan whether he has seen Angelotti. The Sacristan, cowered in fear, uncovers evidence of an outsider's presence in the church: the doors to Attavanti's cappella are opened, and the bas­ket, filled with food, is empty, though the artist had refused to breakfast. Scarpia suspects Caravadossi's involvement with the criminal's escape.
    Tosca enters the church again. She suffers from a jealousy. Scarpia decides to use the singer's hot temper and aroused suspicion. He shows her a fan with the Attavanti's armorial bearings lost by Angelotti, and implies that the artist had gone just with Marquise. The desperate Tosca hastens to Mario's villa, thinking to unmask his faithlessness. Scarpia orders his agents to follow her: Tosca will lead them to the fugitive. Now Angelotti will be caught, but Scarpia discloses one more goal: he wants Caravadossi to be thrown into prison too. And then Tosca - his old passion - will be forced to become his lover.

Act Two

    At Scarpia's cabinet, the Baron waits for Tosca. She would come to him after having sung glorifying cantata at the celebratory gala on the Italian army's victory over Napoleon. Spoletta enters the cabinet. He informs that Tosca was not long at Caravadossi' villa, Angelotti was not found there, but the policemen have arrested the artist.
    Interrogation of Caravadossi didn't give expected results. Caravadossi implores Tosca not to speak also. Then Scarpia commands that the artist to be tortured. Mario's screams during the torture provoke Tosca to reveal the place where Angelotti is hidden - the well. Scarpia sends Spoletta for Angelotti. But their joy is premature: Sciarrone brings news of Napoleon's victo­ry over Italian monarchists at Marengo. Caravadossi does not disguise his joy. Enraged Scarpia commands to imprison him. The artist's will pay his life for his hate to monarchy.
    Toska asks the Baron to liberate Caravadossi. Scarpia promises the forgiveness if Tosca becomes his lover. To save Mario is the main aim for Tosca, and she finally agrees to these demands.
    Scarpia orders Spoletta that Mario will be execut­ed, but the rifles will fire blank catridges. And on the soldiers going away, Tosca with Caravadossi will be able to escape. Scarpia gives her a safe-conduct pass through a frontier.
    But when he attempts to embrace Tosca, she stabs him to death with a knife.

Act Three

    It is Castel Sant'Angelo, where Caravadossi is imprisoned. His impending execution will be in an hour. Mario writes his last letter to Tosca and implores the jailer to deliver it to Tosca.
    Tosca runs in. She shows to Caravadossi the safe-conduct pass from Scarpia and explains him that the shooting will be simulated: he must fall down prompt­ly as he'll hear the first shot, and when the riflemen go away, they will be free. Caravadossi tries to believe in the unexpected pardon and calms his tired friend.
    The jailer takes the artist to be executed. The exe­cution takes place, a report is heard, Caravadossi falls down. Tosca runs to him, but he does not answer. He is shot indeed: Scarpia's promise about the mock exe­cution was a hoax.
    At that moment Sciarone, Spoletta and sbirros are arriving. Scarpia death is discovered, they have to arrest Tosca, But Tosca, swiftly avoiding them, from the higher platform of the castle.