Persephone is used to her role as the queen of the Underworld after a millennium of being married to Hades. However, as time passes, she eventually grows envious of her husband because of his power and desires the same thing.
As each day passes, Persephone's heart blackens and her desire for power grows stronger. The only way for the goddess of the dead to move up the ranks, and become stronger than her fellow deities is to wreak havoc upon both the mortal realm and Mount Olympus.
Meanwhile on Earth, high school sophomore Keisha Parker is hyper-focused on hitting the books so that she can get into a good college which will help her achieve her career goal of being a politician. However, this comes to a screeching halt when her hometown of Thorndale is invaded by an army of sirens, who have claimed the location as a base for Persephone's evil plot.
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.