From the World of Percy Jackson: The Sun and the Star

Synopsis

From 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 reformed titan called bob.