Dramatic fantasy based on Greek myths! As the son of Hades, Nico di Angelo has suffered many losses. Fortunately, there is a ray of light in his life: his friend Will, the son of Apollo. Together, the two are unbeatable. Until now... Because Nico is repeatedly called for help from the depths of Tartarus. It is the voice of the Titan Bob, whom Percy once had to leave behind alone. Nico must go to him – and of course, Will insists on coming along. But can a being of light survive in eternal darkness? And what does the prophecy mean that Nico must "leave something of equal value" down there? For this novel set in the Percy Jackson universe, Rick Riordan has teamed up with award-winning author and queer activist Mark Oshiro, as a young gay couple is at the center of this magical adventure. A Spiegel and New York Times bestselling author! Over 5 million books by Rick Riordan sold in Germany. "Rick Riordan is the rock star of the children's book scene!" Publishers Weekly.