This is the twelfth book in the Anita Blake series. We see a lot of progress in Anita's personal situation in this book, she realizes that she is not giving Nathanial what he needs, that in trying to make herself feel like she is not using him, while making him her Pomme de Sang, that in fact, she is making him feel used. She also manages to forge another Triumvirate, this one between her, Nathanial, and Damian, and in this one Anita is the Master.
Anita also moves to another level in her dealings with the Ardeur, and in the amount of power that her triumvirates wield. During all this, Anita is also trying to help the police solve a serial murder, committed by vampires.