The Bill: Driven to Kill

Following a string of humiliating set-ups by teenagers, Gina clamps down on hoax calls and assigns Will to screen all incoming messages, but the plaintive voice of a youngster claiming he and his brother have been kidnapped by their father convinces Nikki it's the real thing. Confronting the suicidal parent (guest star Ralph Ineson) at the docks, she persuades him to release the children - but only on condition she takes their place in his car