Witchling by Yasmine Galenorn (book 1 of the New York Times Bestselling Otherworld Series)
Berkley (Mass Market); October 2006
We're the D'Artigo Sisters: Half-human, half-Faerie, we're savvy--and sexy--operatives for the Otherworld Intelligence Agency. But our mixed-blood heritage short-circuits our talents at all the wrong times. My sister Delilah shapeshifts into a tabby cat whenever she's stressed. Menolly's a vampire who's still trying to get the hang of being undead. And me? I'm Camille--a wicked-good witch. Except my magic is as unpredictable as the weather, which my enemies are about to find out the hard way...
"At the Wayfarer Inn, a portal to Otherworld and the local hangout for humans and beasties alike, our fellow operative Jocko's been murdered. Every clue points to Shadow Wing, the soul-munching, bad-ass leader of the Subterranean Realms. He's made it clear that he aims to raze humankind to the ground, turning both Earth and Otherworld into his private playground. Our assignment: keep Shadow Wing and his minions from creeping into Earth via the Wayfarer. The demons figure they're in like Flynn. After all, with only my 'bumbling' sisters and me standing in the way, how can they miss? But we've got a secret for them: faulty wiring or not, nobody kicks ass like the D'Artigo girls."