ACT I: At a masked ball at the Capulet palace, Juliette’s (soprano) arrival is eagerly awaited by her cousin Tybalt (tenor) and her suitor Paris. Capulet presents his daughter, the revelers exclaim at her beauty, and Juliette rhapsodizes on her joy. The host leads his guests off just as Roméo (tenor), a Montague, and his friends, all masked, steal into the ballroom intent on provoking a fight. Roméo has dreamed the night before, and Mercutio (baritone), one of his companions, launches into a song about Queen Mab, the mistress of dreams. Suddenly Roméo sees Juliette at a distance. As she waltzes around the room, singing of the freedom of youth, Roméo shyly approaches her, asking if his hand may touch hers. Tybalt returns just as Juliette tells her name to Roméo, who masks himself and rushes off. Tybalt identifies the intruder as Montague’s son, but Capulet restrains him, ordering the party to continue.
ACT II Later that night, Roméo hides until Mercutio and other friends stop calling for him. Then he apostrophizes Juliette as the sun, the purest, brightest star. The girl steps forth on her balcony to lament her attraction for an enemy, and Roméo comes forward. The two ecstatically pledge their love but are interrupted by some Capulets searching for a Montague page. Then Roméo and Juliette tenderly bid each other good night.
At Friar Laurence’s (bass) cell, Roméo appears at daybreak, followed by Juliette and her nurse, Gertrude. The priest agrees to marry the young lovers in the hope that their union will end the feud between their families.
Outside Capulet’s house, Roméo’s page, Stéphano, sings a mocking song, which provokes a fight with Gregorio and other Capulet retainers. Mercutio protects Stéphano and is challenged by Tybalt, who insults Roméo when he tries to make peace. Mercutio duels Tybalt to defend the Montague honor and is slain, whereupon Roméo kills Tybalt. The Duke of Verona stops the bloodshed, banishing Roméo from the city.
ACT III At dawn in Juliette’s bedroom, the lovers exchange words of adoration before Roméo reluctantly leaves for exile. Capulet and Friar Laurence greet Juliette with news that she is to wed Paris that very day, but the priest gives her a sleeping potion that will make her appear dead. He promises that she will wake with Roméo beside her. Juliette drinks the potion, and when Capulet and the others arrive to lead her to the church, she collapses.
In a gloomy tomb, Roméo soliloquizes on his beloved Juliette, whom he believes dead. In despair he takes poison, only to see Juliette awaken. They hail a new life, but Roméo soon falters. He bids farewell to the frantic girl, who grasps his dagger and stabs herself. The lovers die praying for God’s forgiveness.