The Son of Neptune Heroes of Olympus Bo by Rick Riordan

Percy Jackson son of Poseidon God of the Sea has woken from a very deep sleep and come face to face with two snakehaired ladies who refuse to die. But theyre the least of his problems. Because Percy finds himself at a camp for halfbloods which doesnt ring any bells for him. Theres just one name he remembers from his past. Paperback softback