13 Bullets

All the official reports say they are dead-extinct since the late '80s, when a fed named Arkeley nailed the last vampire in a fight that nearly killed him. But the evidence proves otherwise.
When a state trooper named Caxton calls the FBI looking for help in the middle of the night, it is Arkeley who gets the assignment-who else? He's been expecting such a call to come eventually. Sure, it has been years since any signs of an attack, but Arkeley knows what most people don't: there is one left. In an abandoned asylum she is rotting, plotting, and biding her time in a way that only the undead can.
Caxton is out of her league on this case and more than a little afraid, but the fed made it plain that there is only one way out. But the worst thing is the feeling that the vampires want more than just her blood. They want her for a reason, one she can't guess; a reason her sphinxlike partner knows but won't say; a reason she has to find out-or die trying.
Now there are only 13 bullets between Caxton and Arkeley and the vampires. There are only "13 bullets" between us, the living, and them, the damned.