Werewolves and vampires - the highest aristocracy among the undead of the New World - have long hated each other. But young Mercy Thompson is one of her own among both vampires and werewolves. Her lot is to resolve the most complex conflicts between different clans of “night hunters.” This time, resolving the matter peacefully will not only be difficult, but almost impossible. Because one of the most powerful vampires broke the law of his people - and began to kill left and right in order to gain the enormous power that the undead draw from the blood and souls of their victims. Mercy Thompson will have to find and destroy the criminal... unless, of course, he turns out to be faster and more cunning.