Jane Halifax finds herself within the walls of a high security prison, summoned to investigate a murder within the prison's High Security Unit. Five suspects emerge, all psychopaths who have murdered before, but none of whom are known for their ability to work as a team. An impenetrable wall of silence confronts Jane as she tries to determine what conspiracy binds them together. The case brings Jane back into contact with multi-murderer John Garth, whose handiwork has haunted her since she helped put him away. It also reunites her with homicide detective Steve Elliot, who has spent the last three years developing a relationship with Garth in the hope he will reveal details of his last two missing victims.