Sarah investigates a cold case while Lizzie responds to a domestic violence call.

Sarah and Lizzie find themselves working on the same murder case.

The hunt closes in on Brannon and Sarah narrows down the search for Tania’s body.

The Brannon manhunt reaches its climax, and Sarah faces Tania’s killer.

Detectives Sarah Collins and Steve Bradshaw find the bodies of an officer and a 15-year-old Libyan refugee at the Portland Tower in London. The only witness to what happened are a traumatized five-year-old boy and a rookie police officer.

With Lizzie still on the run, Sarah finally persuades her boss, DCI Tim Bailie, to go public about Lizzie’s disappearance. She then makes a series of discoveries about the events that led up to the Portland Tower fall, which further complicate the case.

Lizzie decides to turn herself in, but first she meets Kieran Shaw in secret, who tries to persuade her not to implicate herself. When Sarah finally interviews Lizzie, the explosive truth about what really happened on top of the tower emerges.