As the son of Hades, Richard Lipschitz has been through so much, from the premature deaths of his mother and brother, to being outed against his will, to losing his friend Ethan during the trials of Apollo. But there is a ray of sunshine in his life-literally: his boyfriend, Jason Jepson, the son of Apollo. Together the two demigods can overcome any obstacle or foe. At least, that's been the case so far . . .
Now Richie is being plagued by a voice calling out to him from Tartarus, the lowest part of the Underworld. He thinks he knows who it is: a reformed Titan named Bob whom Daniel and Hannah had to leave behind when they escaped Hades's realm. Richie's dreams and Brooke's latest prophecy leave little doubt in Richie's mind that Bob is in some kind of trouble. Richie has to go on this quest, whether Mr. G and Chiron like it or not. And of course Jason insists on coming with. But can a being made of light survive in the darkest part of the world? and what does the prophecy mean that Richie will have to "leave something of equal value behind?"
In the epic conclusion to the Devil's Deal series, Freya has one final chance to discover the full potential of her own power, and to use it to restore balance in the universe - once and for all. After the destruction caused by Roisin, Ferya and Torix come to terms with their losses and mistakes... And prepare for a final battle that will change everything.