Enters the world of Colin Stagg, the Met Police's prime suspect. In officers' minds, Stagg perfectly fitted the criminal profile of the killer, and yet there was no hard evidence linking him to the murder. Their hopes of a conviction rested on the involvement of undercover officer Sadie Byrne in his life.
Stars: Niamh Algar, Eddie Marsan, Sion Daniel Young
Director(s): Niall MacCormick
Writer(s): Emilia di Girolamo