When the female killer strikes at the very heart of Fitz's own family he must use all his powers of interrogation to find his son before it's too late.

A lab technician, working at the same university as Fitz, begins to electrocute male students in order to gain the attention of the psychologist.

Fitz is pitched against Grady and Nash, whose relationship is now spinning dangerously out of control.

Stuart Grady, a lonely factory foreman, befriends a young male employee and the disturbed runaway involves them both in murder.

As DS Jimmy Beck and DS Penhaligon face up to the dramatic events of the past.

DS Penhaligon has no choice but to work with DS Beck despite her conviction that he raped her.

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.