Act I: The church of Sant’Andrea della Valle in Rome, 1800
The escaped political prisoner Angelotti hurries into the church and hides in a side chapel. Mario Cavaradossi, a painter, arrives to add the finishing touches to his portrait of Mary Magdalene. The painting blends the image of his beloved Floria Tosca with that of an unknown woman whom he saw recently praying in the church. Angelotti emerges from hiding and tells Cavaradossi of his escape, then hides again when they hear Tosca’s voice outside. She enters and is disturbed by the painting’s resemblance to someone other than herself. Cavaradossi assures her of his love and she departs. As Angelotti reappears, a cannon shot signals the discovery of his escape and the two men hurry away to Cavaradossi’s villa. Baron Scarpia, chief of the Roman police, enters and finds evidence of Angelotti’s recent presence, including a fan belonging to Angelotti’s sister. When Tosca returns, Scarpia uses the fan to inflame her jealousy. Scarpia gloats over the anticipated destruction of his rival and the conquest of Tosca.
Act II: Scarpia’s apartment in the Farnese Palace
As Scarpia dines alone, his deputy Spoletta arrives with the news that Cavaradossi has been captured but Angelotti cannot be found. When Cavaradossi refuses to reveal the fugitive’s whereabouts, Scarpia orders him to be tortured while Tosca is forced to listen. Unable to stand the sound of Cavaradossi’s agony, Tosca reveals where Angelotti is hidden and Cavaradossi curses her weakness. Scarpia orders Cavaradossi to the gallows and then tells Tosca that, if she will submit to his embrace, he will release her lover. After Tosca agrees to this, Scarpia tells her that he cannot simply pardon Cavaradossi and instead will stage a mock execution before setting him free. Tosca insists that he write a note of safe passage for both her and Cavaradossi to escape Rome. After he has sealed the note, Scarpia advances on Tosca to claim his reward and she stabs hi to death. Tosca grabs the note of safe passage and quickly flees.
Act III: The Castel Sant’Angelo
In his prison cell, Cavaradossi hears a passing shepherd boy sing, then remembers his first night of love with Tosca. She appears, explains about the mock execution, produces the note of safe passage, and describes how she killed Scarpia. Cavaradossi commends Tosca and they are both led to the top of the tower as the firing squad readies itself. After the shots are fired, Tosca races to her lover and bids him to rise, only to discover that she has been tricked and Cavaradorri is, in fact, dead. Her grief is interrupted by the arrival of Scarpia’s henchman Spoletta, who has discovered the baron’s body. In final despair, Tosca leaps over the parapet to her death.