Madeline Black is an Agent of death, meaning she escorts the souls of people who have died to the afterlife. But lately, some spirits don't feel like crossing over... Something is wrong with the souls of Chicago's dead. Ghosts are walking the streets, and Maddy's boss wants her to figure out why. At the same time, the pact that Maddy unwittingly made with the local werewolves comes back to bite her when their alpha is kidnapped. As Lucifer's heir, she should be able to discover who—or what—is responsible for both occurrences, but the fallen haven't been too happy with her since she agreed to harbor Gabriel's half brother, Samiel. And while work is bad enough, Maddy has a plethora of personal problems, too. Now that Gabriel has been assigned as her thrall, their relationship has hit an impasse. At least her sleazy ex-fiancé, Nathaniel, is out of the picture—or so she thinks...