DS Sarah Collins and her colleague, DC Steve Bradshaw, investigate the deaths of long-serving police officer, PC Hadley Matthews, and a 15-year-old Libyan refugee, Farah Mehenni.
With Lizzie still on the run, Sarah finally persuades her boss, DCI Tim Bailie, to go public about Lizzie's disappearance.
Lizzie decides to turn herself in, but first she meets Kieran Shaw in secret, who tries to persuade her not to implicate herself.
Sarah investigates a cold case; Lizzie responds to a domestic violence call.
Sarah and Lizzie find themselves working on the same murder case.
As the manhunt closes in on Brannon, Sarah realises where Tania's body might be buried.
Gemma Whelan
DS Sarah Collins
Tahirah Sharif
PC Lizzie Adama
Jimmy Akingbola
DC Steve Bradshaw
Emmett Scanlan
DI Kieran Shaw
Nick Holder
PC Hadley Matthews