The war between Good and Evil has raged for millennia, with the Marked Souls caught in the middle. Now two lost souls will tip the precarious balance.

Possession by a demon cost Jonah Walker his faith, his humanity, and his wife. Once a righteous missionary, he endures immortality with nothing but a body for battle and a bent for retribution. But his last devastating fight left him wounded beyond healing, and his only chance to redeem his soul lies with a fallen woman.

Thrust into a wicked underworld of shadows and sin, Nim Hamlin can't believe her wanton ways as the "Naughty Nymphette" enthralled a demon—and a damned saint. The world she knows doesn't deserve deliverance. But the touch of this good man's hand holds an unholy allure—and she's never been any good at resisting temptation.

As darkness gathers in the sweltering Chicago summer, Jonah and Nim must conquer the demons of their past to face even fiercer monsters in one last assault. But first they must put aside their doubts and disbeliefs and let their passion for each other burn through the shadows to ignite a furious power.