

Further examination of David Walker's history suggests that he was a troubled man with a number of issues. Marion has a prickly chat with Cassie about her past and the investigation reveals her close relationship with an IRA activist. As the police enquiries encroach on their lives, Sara and Colin open up to their partners.
Detectives Cassie and Sunny reunite as they take on a case concerning the remains of a body found locked in a suitcase in the River Lea. As the pair begin the complicated task of trying to identify the body, the stories of four people with apparent links to the victim begin to unfold. Old wounds are reopened when the detectives track down the victim's wife and son, who have been in the dark about his disappearance for 26 years. Who wanted the man dead and why?