The Tower

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, who have fallen from the roof of Portland Tower in south-east London.

With Lizzie still on the run, Sarah finally persuades her boss, DCI Tim Bailie, to go public about Lizzie's disappearance, 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.

Sarah investigates the disappearance of a teenage girl, missing for 25 years. Lizzie returns to Farlow and gets called out to in a nasty case of domestic violence.

Sarah and Lizzie must work together to track down a murderer and a missing child. A new suspect emerges in Sarah's investigation into Tania Mills' disappearance.

Thanks to Lizzie the police manhunt closes in on Brannon and Skye. Sarah develops a new suspect in the Tania case and gets a clue as to where Tania's body might be buried.