Caroline is technically the servant of Nicholas, the Master vampire who reigns over the west coast of the United States. In reality, she's too powerful in her own right to be forced into a submissive role. Instead, Nicholas has made her his emissary. In Arizona, she faces a danger long thought to be extinct. She needs to trade her services as a sorceress, and those of the werewolves who follow her, for an antidote she desperately needs to save one...