Set six months after the House of Hades, and in the Harry's fifth year at Hogwarts. Percy Jackson, Son of Poseidon, Hero of Olympus and more recently, Survivor of Tartarus, has been given a quest. Along with his two cousins Nico Di Angelo and Thalia Grace, he must go undercover at Hogwarts School of Witchcraft and Wizardry for a year. Their objective? Protect Harry Potter, Ron Weasley and Hermione Granger. Harry has had a rough summer, what with the dementor attack and the Dursleys. He thinks life back at Hogwarts will turn things around, only to realize that he is facing a year of ignorance and scorn. When the golden trio meet the children of the Big Three, will they become friends, or worst enemies?