Lux Windsor knew from the time she was a small child that she had been born for battle. The daughter of a witch and a vampire, she has trained for her part in the destruction of Lucifer for as long as she can remember. Along with Zane, the son of the Angel of Death and a witch, Lux is tasked with finding, and killing, all the children of Beelzebub, one of the most powerful Devils in existence. Only by severing his link to his children can Beelzebub then be killed, which could weaken Lucifer enough that he could be defeated.

As they battle toward victory, Lux and Zane are forced not only to fight against Cambion, but to battle Devils and Angels as well in a fight to remain alive, and to remain together. Forced to link their minds together in order to survive, Lux and Zane struggle to adjust to their new reality, while continuing on their quest to kill Beelzebub.
Already dealing with the loss of two of their own, Lux and Zane are determined to get through their task with no more death. However, as they are sucked into Purgatory for the final battle, the stakes are higher than they've ever been. After all, if you're killed in Purgatory, there is only nothingness, without even the comfort of knowing those lost ascended to Heaven. Faced not only with Beelzebub, but with Lilith, Azazel and a veritable army of Cambion, Lux is forced to face the possibility that not everyone she loves will survive. With victory just slightly out of reach, Lux and Zane must choose whether to stay the course and ensure Beelzebub dies, or divert from their path in order to save those they love.