In New York City, Zeus and Poseidon meet at the top of the Empire State Building, where Zeus reveals that his master lightning bolt has been stolen and accuses Poseidon's demigod son, Percy Jackson, of the theft. Poseidon reminds him that Percy is unaware of his true identity, but Zeus declares that unless his master bolt is returned to Mount Olympus before the summer solstice, in two weeks' time, war will be waged between all the gods.