Percy Jackson discovers he's a demigod, the son of Poseidon, after his math teacher turns into a monster and attacks him. He's sent to Camp Half-Blood, a safe haven for kids like him, where he learns that Zeus's master lightning bolt has been stolen—and he's the prime suspect. To clear his name and prevent a war among the gods, Percy embarks on a dangerous quest across America with his friends Annabeth and Grover. Along the way, he battles mythical creatures, solves ancient riddles, and uncovers a plot that threatens the entire world.