Return of the crime thriller about a police anti-corruption unit. A hardened criminal is shot dead by an armed-response unit led by Sgt Danny Waldron, who claims they were acting in self-defence when interviewed by Hastings and Arnott. To find out more, DC Kate Fleming is sent undercover into Danny's team, and she is quick to identify tensions between the officers - only for her own conduct to come under scrutiny. Daniel Mays stars as the suspect, with Vicky McClure, Martin Compston, Adrian Dunbar, Arsher Ali and Will Mellor.