Demigods Nico di Angelo and Will Solace must endure the terrors of Tartarus to rescue an old friend in this thrilling adventure co-written by New York Times #1 best-selling author Rick Riordan and award-winning author Mark Oshiro. Percy Jackson fans, rejoice! Nico and Will have a book of their own! As the son of Hades, Nico di Angelo has been through so much, from the premature deaths of his mother and sister, to being outed against his will, to losing his friend Jason during the trials of Apoll