Bone Crossed - Patricia Briggs

Welcome to Patricia Briggs's world, a place where "witches, vampires, werewolves, and shape-shifters live beside ordinary people" (Booklist). It takes a very unusual woman to call it home—and there's no one quite like Mercy Thompson.

By day, Mercy Thompson is a car mechanic in the sprawling Tri-Cities of Eastern Washington. By night, she explores her preternatural side. As a shape-shifter with some unusual talents, Mercy's found herself maintaining a tenuous harmony between the human and the not-so-human on more than one occasion. This time she may get more than she bargained for.

Marsilia, the local vampire queen, has learned that Mercy crossed her by slaying a member of her clan—and she's out for blood. But since Mercy is protected from direct reprisal by the werewolf pack (and her close relationship with its sexy Alpha), it won't be Mercy's blood Marsilia is after.

It'll be her friends'.