18-year-old Maya has always known the rules for banishing ghosts - but she never imagined she'd be banishing the ghost of her ex-girlfriend, Alana. After years of emotional abuse, Maya finally finds the courage to break up with Alana, stranding her on the remote trail where they'd been hiking. Seeking space, Maya flees her Los Angeles hometown for her older sister's lake house. The sleepy small town of Lake Ember feels like the perfect place to heal; at least, until Alana turns up dead right on her doorstep. Alana's ghost appears, desperate to come back to life, and blackmails Maya: if Maya doesn't help her possess a girl in town, Alana will frame Maya for her murder. Even more complicated, Maya finds herself falling for Alana's possession target; Rowan, the girl whose life she has endangered.