Abandoned and left as an orphan, Wren Williams is on a search to find where she comes from—a difficult task since she's the only siren in The Hartlands, a city in The Upper Hollows. 

When Shifter Homicide Detective Kai, her friend's older brother, says he'll find her family, she jumps at the opportunity. While she's always sensed a level of attraction between them it was something Kai and Wren ignored for professional reasons because their jobs tend to overlap. 

When bodies with missing organs begin to show up at the morgue, Wren worries her first job as a forensic pathologist is colliding with her part-time job as a monster tracker. 

Then the unthinkable happens: a friend is murdered, intertwining Wren and Kai even more, taking them on a journey to solve the case. 

Can Wren find her family while juggling a possible relationship, solving murders, and tracking monsters? Or will she perish when the things that go bump come for her?