Metamorphoses Book 7: Medea and Pelias: Her Flight
Medea left her home and went to Pelias pretending that she and Jason weren't getting along. Pelias' daughters welcomed and befriended her, but all along she was plotting. She told them how she'd made Aeson young again, and so Pelias' daughters asked her to do the same for their father. She showed them the ritual with a sheep so that they could see how she refilled the animal's emptied veins with the youth potion. When she performed the rite on Pelias, she asked his daughters to drain the blood from his body, and he awoke as they were cutting him. Medea let him die, leaving his daughters as his murderers.
Medea went back to Corinth where Jason had a new wife. She burned the palace and killed the children that she had borne to him. Then she rode away on a chariot drawn by dragons and married Aegeus.