A near-death experience, a horrible incident at school, and a move from Connecticut to Florida have turned seventeen-year-old Pierce's life upside-down, but when she needs him most John Hayden is always there, helping but reminding her of her visit to the Underworld.

Demi-god Percy Jackson and his friends must journey into the Sea of Monsters to save their camp. But first Percy will discover a secret that makes him wonder whether being claimed as Poseidon's son is an honor or a cruel joke.