A new threat is rising, Tartarus. The sons of the Big Three are called to face this new foe. To do so they all have to claim their true power. Otherwise Tartarus and every monster in his pit will destroy everything. Percy Jackson: Son of Poseidon- He made it through high school. He and Annabeth are going to make a life in New Rome. But Percy's plans get cut short by a new danger. Jason Grace: Son of Jupiter- So far Jason has kept his promise. He's been building shrines and remembering the mistreated and forgotten Gods. But now he has to put his project on hold to protect what he loves. Nico di Angelo: Son of Hades- Nico has been playing nice. Living at Camp Half-Blood with Will has made him happy. Or as close to happy that he's ever been. But when a new threat rises, Nico won't let what he cares about get hurt.