Months after the end of the Second Titan War, Percy Jackson is lost and despondent. They won the war, but victory came at far too high a cost. Then, while exploring the depths of the sea for monsters to fight and secrets to discover, Percy finds himself sucked through to a strange new world without gods and monsters. Where is he? What is going on? And why are all these crazy mortals with super powers running around fighting each other in silly costumes?