Idomeneas, the King of Crete, who was praised for his bravery at the Trojan War, encounters a terrible storm in his way back home. He asks Poseidon for help and pledges to sacrifice the first being he meets on shore in exchange for survival at sea. But the first person he encounters turns out to be his own son, Idamante. Idomeneas refuses to sacrifice his son and Poseidon punishes him by sending plague to Crete. Idomeneas ends up expatriated by his own people.