The Harlequin (Anita Blake, Vampire Hunter) by Hamilton, Laurell K. [MassMarket(2008/4/29)]

Anita Blake is a vampire hunter, but now finds herself becoming the hunted. Malcom, Leader of the vampire church, asks Anita Blake for help fighting demons. But Anita begins to see warning signs from the Harlequin. "Anita Blake has the authority to pass judgment on vampires. The Harlequin have the authority to pass judgment on her. It is forbidden to speak of the harlequin unless you've been contacted. And to be contacted by the Harlequin is to be under sentence of death."