The Morganville Vampires, book 5 of 15, completed series

Morganville, Texas. Just south of normal.

In the college town of Morganville, vampires and humans coexist in (relatively) bloodless harmony. Then comes Bishop, a master vampire who threatens to abolish all order, revive the forces of the evil dead, and let chaos rule. 

But Bishop isn't the only threat. Violent black clouds promise a storm of devastating proportions. As student Claire Danvers and her friends prepare to defend Morganville against the elements, both natural and unnatural, the unexpected happens: Morganville's vampires begin to vanish one by one. 

Discovering why leads Claire to one last choice: swear allegiance to Bishop or die.