Newly promoted Detective Inspector Theophilus Blackwell is assigned the case of Lorna McCauley, which on the outside seems to be a simple case of mid-life crisis and child abandonment. Elsewhere in London, MI5 analyst, Sophia Evans, is working undercover to catch an animal rights group responsible for targeted bombings. As Sophia's case (and her personal life) fall to pieces, she receives a strange envelope in the mail. It contains a picture of Lorna McCauley's lifeless face along with a daunting code.
Now the police and MI5 are forced to work together to stop the murders, and Sophia must find her way into the terrifying mind of a serial killer."