Blood Bound
By Patricia Briggs, 2007
Series: The Mercy Thompson Series

Mechanic Mercy Thompson has friends in low places-and in dark ones. And now she owes one of them a favor. Since she can shapeshift at will, she agrees to act as some extra muscle when her vampire friend Stefan goes to deliver a message to another of his kind.

But this new vampire is hardly ordinary-and neither is the demon inside of him.

Order Info: ISBN 0441014739, Ace