Porgy and Bess have found each other, and are living contentedly in their love. She’s a former good time girl, mistress of a hoodlum on the run who’s looking for her. Porgy’s a cripple, laughed at by others, but not by Bess, who feels safe in his arms.
As the curtain rises, we’re in Charleston, South Carolina, where a group of locals is being entertained by blues player Jasbo Brown. The men are warming up for a game of craps, but a young mother, Clara, takes no notice, singing a lullaby to her baby.
As Scaria prepares to take her, Tosca picks up a knife and kills the monster. Cut to Cavaradossi, who awaits his death, and his mind and heart are full of Tosca. Overcome with memories of love, he writes a last letter, recalling sweet nights of happiness.
Tosca is brought before Scarpia and forced to listen to the cries of her tortured lover, until she gives up the fugitive's whereabouts. Scarpia offers Tosca the chance to save her lover’s life- on condition she submit to Scarpia’s pleasure.
Tosca visits Cavardossi at the church, and then he leaves to shelter fugitive Angelotti. Police chief Scarpia enters. Tosca returns but meets Scarpia, who convinces her Caverdossi is cheating. She leaves, distraught. Scarpia sings of his desires.