The plot centres around a love triangle: Egée wants to marry his ward, princess Églé, while the sorceress Médée wishes to marry the young warrior Thésée, but Thésée and Églé love each other. Médée attempts to force the lovers to renounce each other: first by using her magic to bring Églé to a place of torment, then by convincing Egée to have Thésée killed as a potential threat to his reign. But before Thésée can drink the poison he has been given, Egée realises that Thésée is his lost son. He then gives Églé to Thésée. Médée takes vengeance by destroying the festive setting, but the goddess Minerve undoes this.