Outside the palace of King Créon
Dircé is preparing for her wedding to Jason. However, with Médée's help, he had stolen the golden fleece and, in doing so, Médée had betrayed her family and established a relationship with him, the result of which was her two children. Although Jason had since abandoned Médée, she reappears and demands that he return to her. Jason refuses and Médée curses him, swearing vengeance.
Inside the palace
Despairing, Médée is encouraged to leave the city by her slave, Néris. However, Créon appears and orders that Médée leave. She asks for one more day with her children and, after the king agrees, she appears to be calmer and gives Néris two wedding presents to take to her rival.
Between the palace and the temple
Néris brings the two children out to where Médée is waiting. Sounds of lamentation are heard from within the palace and it is discovered that one of Médée's wedding presents has poisoned Dircé. An angry crowd gathers and Néris, Médée, and the children take refuge in the temple. The two women reappear with Médée grasping a blood-stained knife with which she has killed her two children. The temple, to which Médée returns, goes up in flames.