Thalia Grace
Thalia appears in Percy's dreams throughout the book. At the end of The Sea of Monsters, she is brought back to life by the Golden Fleece which Clarisse places on her pine tree. Zeus gives her a spear which shoots electricity and turns into a small mace canister that fits in her pocket, and Athena gives her a bracelet that turns into Aegis, a shield with the Medusa's head carved into it. It is a replica of her father’s. Thalia is now potentially the child of the prophecy, and Kronos soon takes advantage of the fact. in the sea of monsters Percy uses the sea as a compass to navigate to find the golden sheet which will bring back Thalia as her tree was dying in front of the camp