Shattered Soul - Darkness Summons, #3

Cass doesn't know if she's a light or a dark siren. Wait, what? Oh, no. And she's learned too many secrets about her family. More than she ever wanted to know. Now her cousin's been abducted and Cass is the only one who seems to care. She's got to find her missing cousin. Of all the people to have help her, did it have to be Kai Sinclair? The hot beast who seems to be nice to everyone but her. Okay, well, truthfully, she'd like to make his blood boil until he's dead.
Yeah, those aren't the makings of a good friendship, are they?