The war between good and evil has raged for millennia, and as a powerful new enemy ascends, the Marked Souls are pushed to the ragged edge.

Sidney Westerbrook has always studied darkness and damnation from a sensible distance. Now, to earn his place as a league Bookkeeper, he must discover why Chicago is such a battleground of soul-linked warriors. But the research becomes personal when he finds himself over his head and under attack—and at the mercy of a waif with demon-lit eyes and a deep yearning in her heart.

Alyce Carver has been alone longer than she can remember, battered by the living nightmares that haunt her city. Cornered by yet another gang of demons, she unwittingly joins forces with a handsome scholar who can salvage her past, and she in turn may be the key to his investigations. But she won’t let him go until he shows her everything she’s been missing.

What begins as an experiment in possession becomes a trial by desire so powerful it threatens both their lives, even as it binds their souls.