Percy Jackson, a trouble maker, finds out that he's a demi-god and that his father is a greek god. He was at the beach with his mother when all of a sudden he is informed that he has to go to camp half blood to seek safety from the monsters that are after him.
He's safely at camp half blood, he wasn't used to everything there but got to meet alot of demi-gods and half bloods like him which made it easier for him to learn about himself. He then found out that someone had stolen Zeus's lightning bolt. Him being Poseidon's son made him get blamed for it.
As Percy's begins the quest with Annabeth and Grover to find the master bolt to refuse to allow any wars between Zeus and Poseidon. Percy thought that he wasn't ready but he had to save the world.