The play reflects the tenets of Romanticism - the main theme is tragic love, and supernatural motifs appear.
The story takes place in an unspecified corner of Germany. Odetta, enchanted by the evil sorcerer Rothbart, leads a life in the guise of a swan, as Queen of the flock. Siegfried is a prince who is faced with choosing his future wife at an upcoming ball.
In Act I, the prince and his friends decide to hunt swans and head to the lake. At one point, Siegfried gets separated from the rest of his companions, led by the Evil Spirit disguised as an owl.
In Act II, the young man notices birds landing but stops firing his crossbow when one of them turns into a beautiful girl - Odetta. Odetta tells him her story, and the young man falls in love with her.
Act III focuses on the engagement ball, but the prince, enchanted with Odetta, pays no attention to potential candidates. Everything changes when Rothbart enters the hall with his daughter Odilia (the black swan) who, as a result of the spell, resembles the Swan Queen. The unaware prince begins to dance with Odilia and expresses his will to marry her. Odetta, who observes the entire scene through the window, flees to the lake. Siegfried realizes his mistake and follows his beloved, but it is too late.
In the last Act IV, Siegfried meets Odetta again at the lake, but the spell cast on the girl can no longer be removed because Siegfried pledges his love to another. The girl decides to kill herself so as not to spend the rest of her life in the guise of a bird. She throws herself into the lake, and the prince follows her. The act of sacrificing their lives takes the spell off the rest of Odetta’s companions, who regain their human form. The Evil Spirit is defeated, and the lovers ascend to heaven, being bound to each other forever.
