It's been three years since Percy Jackson and Harry Potter met. The Giant War was long over, and the Battle of Hogwarts was successful. But when a new threat rises in the mythological world, the two camps aren't enough, and Percy has no choice but to call reinforcements from Hogwarts. _-_-_-_-_-_-_-_ Harry was nothing but confused when a strange man with a weird resemblance to himself showed up at his door. Even weirder, he wanted Harry's help in another battle.