Percy has now learned that he is the son of the Greek god Poseidon. He has also learned that their might be a possible war between Poseidon and Zeus, over Zeus’s lightning bolt. So Percy has been sent on a quest to find the lighting bolt and to stop this war. But Percy’s real reason for going to get the lightning bolt is to save his mom from the underworld. On his quest he meets many monsters that have been sent by Hades to kill him.