Part 1 of 2. When an East End father and son are killed in a road accident, Nikki and Jack find themselves working alongside a police officer with a vendetta. Clarissa summons her husband Max, a digital forensics expert, to help crack the case and he uncovers disturbing video evidence.
Part 2 of 2. Nikki is under fire for leaking information on a suspect, and Thomas is called in to play peacemaker. Jack and DI Ashton track down the mystery witness. Before the killer strikes again, the team must uncover the true story of Ruth Tresize's disappearance three years earlier.
Part 2 of 2. Having found a link between the two cases, the team struggles to make sense of it. Nikki visits a disgraced former colleague who may hold the key. Thomas uncovers the bizarre truth about how Tina died.