Description: After months of fruitless investigation, DCI Roz Huntley (Thandie Newton, Westworld) 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, W1A) briefs AC-12 to investigate. AC-12’s Supt Hastings (Adrian Dunbar, Ashes to Ashes) places DS Kate Fleming (Vicky McClure, The Secret Agent) undercover inside Roz’s team to discover the truth. With DS Steve Arnott (Martin Compston, Sweet Sixteen) 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.