Line of Duty

After months of fruitless investigation, DCI Roz Huntley (Thandie Newton) is under intense pressure from her superiors to apprehend a serial killer responsible for the murder of two women. When a third victim is abducted, Roz makes a breakthrough and apprehends the suspect--but the case is far from open-shut. With doubts around the investigation swirling, Chief Forensic Investigator Tim Ifield (Jason Watkins) alerts AC-12 to investigate.

AC-12's Supt Hastings (Adrian Dunbar) places DS Kate Fleming (Vicky McClure) undercover inside Roz's team to discover the truth. With DS Steve Arnott (Martin Compston) piling on pressure from the outside, Roz is forced to act decisively. But as suspicions mount and the conspiracy deepens, AC-12 soon find themselves under threat.