An abrasively eccentric forensic psychologist aids in the solving of difficult police cases.
Cast: Robbie Coltrane, Geraldine Somerville, Kieran O'Brien, Barbara Flynn, Lorcan Cranitch, Ricky Tomlinson, Tess Thomson, Christopher Eccleston, Wil Johnson, Nelsan Ellis, Natasha Alam, Leon 'Lee' Fuller, John Hillard
Fitz is taken off the case when it is discovered the killings are for him. Determined to catch Fitz's attention, Janice targets Mark.
A lab technician, working at the same university as Fitz, begins to electrocute male students in order to gain the attention of the psychologist.
Nash and Grady cross paths with Nash's former foster parents, which triggers Nash's long-harbored vendetta towards them, particularly their little boy. Still coping with Jimmy Beck's death, the police bring Fitz in to help catch Nash.
Stuart Grady, a lonely factory foreman, befriends a young male employee and the disturbed runaway involves them both in murder.
Maggie Harvey, David's wife, is discovered to be the second killer, but her confession to the first murder means David will be set free. Jimmy Beck finally reaches his breaking point and sets out to punish David otherwise.
David Harvey is arrested, but while he is in custody, two more identical killings occur, casting doubt on his guilt. Jimmy Beck, meanwhile, cannot get over his guilt over Bilborough's death and raping Penhaligon.
A married father of four, addicted to kinky sex with prostitutes, kills one when he cannot pay and she threatens to expose him to his wife.