At Grave's End Night Huntress Series, Book 3.

Some things won't stay buried ... at grave's end. It should be the best time of half-vampire Cat Crawfield's life. With her undead lover Bones at her side, she's successfully protected mortals from the rogue undead. But though Cat's worn disguise after disguise to keep her true identity a secret from the brazen bloodsuckers, her cover's finally been blown, placing her in terrible danger. As if that wasn't enough, a woman from Bones's past is dete...