She is a teenager who does the normal things - school, martial arts, working at an animal shelter... But she is obsessed with serial killers and thinks she might be one in time. She knows she is different from other kids and her loving family, that she has a darkness inside her. 
 She is currently fascinated with the case her BAU Mother is investigating - The Decapitator. And then he/she contacts her - knows she is following the case. The worst part for Lane, the killer seems to be very close to her. 
 I really enjoyed this story with it's twists and turns and intense self reflection and questions re. nature vs. nurture in the development of serial killers.