A three-part documentary series focusing on Lancashire Police's major investigation team begins with an investigation into the rape of a young mother. The rapist found his victim through a dating website, but will Sergeant Sheralyn Melton be able to gather enough evidence against the suspect to be able to charge him? When a man is stabbed to death near Blackpool town centre, Detective Superintendent Andy Murphy launches a manhunt for the killer. The suspect, who has a previous history of violent offending, uses a number of aliases and travels long distances to different locations to evade being captured. Will the police be able to find him?