rom New York Times #1 best-selling author Rick Riordan and award-winning author Mark Oshiro comes a new standalone adventure featuring two of the most popular characters from the world of Percy Jackson and the Olympians.

ONE PROPHECY. TWO DEMIGODS. A HEROIC QUEST.

Nico di Angelo is pretty familiar with the realms of death, being the son of Hades and all. So when a desperate voice starts plaguing his dreams, Nico is convinced it's coming from the Underworld and belongs to an old friend - a ref...