Overview: Nikki and Jack strive to track down a sniper at large in London and stem a public crisis.
Overview: Nikki and Jack investigate links between the victims to close the net on the killer.
Overview: Nikki and Jack investigate a man killed by a train on the London underground.
Overview: Nikki helps high-flying DI Luke Nelson unearth painful childhood memories.
Overview: A suspected paedophile is found murdered in a children's playground.
Overview: Nikki, Jack and Thomas focus in on Lizzie's movements on the night of Barge's murder.
Overview: The nanny of a Russian oligarch is killed in a botched assassination attempt.
Overview: A young woman working for the Doshis is found dead in Maksim's apartment.
Overview: The Lyell team are under pressure to catch the killer of an admired Essex police officer.
Overview: When the body of local criminal Jason Simons is found, the course of the case is changed.