Jennifer Rardin 
Bitten To Death 
Book four in the Jaz Parks sequence

Jaz Parks, assassin and black ops agent, is plunged head-first into her latest mission – a confrontation between her ancient vampire boss Vayl, and his previous undead allies. The CIA is hunting arch-criminal Samon, and needs Vayl’s ex-friends for information. But the team will have to wade through knotty vampire politics, a were-on-were blood-fest and some nasty (oh, and blood smeared…) visions to get to it. Luckily Jaz’s highly trained killing-machine brother is on the job. Unluckily, he has reached the end of his carefully hoarded sanity, and the mission targets suddenly don’t seem quite so realistic. The last thing Jaz wants is to end up on the dead side of the balance sheet …