In 1928 Chicago, eighteen-year-old Ruby, daughter of the state attorney, uses her ability to read minds as a vigilante to hunt out murderers and kill them even if they have not yet committed the crime; Guy works in the morgue, and wants to understand the human body, because maybe then he will learn how it is that he is able to shapeshift into other people--something Ruby plans to use because someone is out to get her father and she is pretty sure it is the police, not the gangsters.