Deathwish — Rob Thurman

How I felt the mental stirrings of a bloodthirsty heritage when I passed through the gray light wasn't my favorite topic.... The Auphe nature wasn't mine. I wouldn't let it be. And if I said that to myself over and over and sprinkled around enough frigging fairy dust, maybe it would be true.

Half-human Cal Leandros and his brother, Niko, are barely getting by with their preternatural detective agency when the vampire Seamus hires them. He's being followed, and he wants to know by whom. But the Leandros brothers have to do more than they had planned when Seamus turns up dead (or un-undead).

Worse still is the return of Cal's nightmarish family, the Auphe. The last time Cal and Niko faced them, the Auphe were almost 1 wiped out. Now they want revenge. Cal knows that before the Auphe get to him, they will try to destroy everything and a everyone he holds dear. Because for the Auphe, Cal's pain is I , a pleasure.

And they're feeling good.