You should never trust a psychopath. But what if you had no choice? It would be easy to underestimate Chloe Sevre... She's a freshman honor student, a legging-wearing hot girl next door, who also happens to be a psychopath. She spends her time on yogalates, frat parties and plotting to kill Will Bachman, a childhood friend who grievously wronged her. Chloe is one of seven students at her DC-based college who are part of an unusual clinical study of psychopaths--students like herself who lack empathy and can't comprehend emotions like fear or guilt. The study, led by a renowned psychologist, requires them to wear smart watches that track their moods and movements. When one of the students in the study is found murdered in the psychology building, a dangerous game of cat and mouse begins, and Chloe goes from hunter to prey. As she races to identify the killer and put her own plan for revenge into action, she'll be forced to decide if she can trust any of her fellow psychopaths--and everybody knows you should never trust a psychopath.