Neptune sent Cetus, a sea monster, to go and destroy the lands on the coast. Many people and animals were killed. Andromeda's father went and asked an oracle, who could consult with the gods, what he could do to stop the monster. The oracle sadly told Cephus that the only way to stop the monster was to sacrifice Andromeda. The king had Andromeda chained to a rock near the sea for the sea monster.

Perseus was coming back from killing Medusa. Medusa's hair was turned into snakes by another goddess who became angry at Medusa's pride of her hair. Anyone who looked at Medusa was changed into stone. Perseus fell in love with Andromeda and held up Medusa's head, changing the sea monster into stone. After Andromeda was saved, they married and lived happily ever after.