Five long years have passed since Chicago's notorious mob boss, Rio, lost the love of his life to the Underworld again. Lynne never showed up to their promised date and he's certain something terrible must have happened to her. However, his life takes a tragic turn when his daughter is murdered by a Deathwalker. Unwilling to give up, Rio dares to do the unthinkable and summons the Bone Queen. He sacrifices his own soul and takes on his fate in the Underworld. But there's a catch: he must hunt down 100 runaway souls to pay for the spell. And one of them is the queen's missing bone thief, Lynne.Lynne has returned to the Underworld after making a series of dangerous deals - but at a steep cost. The Bone Queen knows of her treachery and seeks to punish her. On the run and heartbroken since Rio never showed up on Storm Day, Lynne turns to the Blood Queen for help. Again. The dark witch offers to join forces and bring an end to her sister. As fate would have it, Rio and Lynne cross paths once more, but this time they find themselves on opposite sides of a treacherous battle. One of the queens is hiding a dark secret that threatens to destroy all worlds.As they unravel the lies, curses and ancient secrets, they must make a choice - to believe the Bone Queen or the Blood Queen. But who is lying?