After helping Jason to retrieving the Golden Fleece thanks to her magic arts and deceptions, Medea is repudiated by the Greek hero. Therefore, the Colchian sorceress plots a vicious revenge on Jason, who abandoned her to contract a new marriage with Creusa, daughter of Creon, king of Corinth.
Creon gives Medea an ultimatum: to leave Corinth in one day, before getting exiled. But, despite Jason's invitation to go away peaceably, she decides to stay in the Greek town and to exact her vengeance, sending to Creusa a poisoned robe as a wedding gift. Jason's betrothed and his father die because of the fire broken out by the mantle sent by Medea.
However, despite a doubled murder, her wrath doesn't seem to quite: as an extreme gesture, the witch kills both of her sons before the eyes of their father, Jason, throwing their lifeless bodies to him.
