What happens after you've saved the world? Well, if you're Rachel Mariana Morgan, witch-born demon, you quickly discover that something might have gone just a little bit wrong. That the very same acts you and your friends took to forge new powers may have released something bound by the old. With a rash of zombies, some strange new murders, and an exceedingly mysterious new demon in town, it will take everything Rachel has to counter this new threat to the world—and it may demand the sacrifice of what she holds most dear.