In the town of Blackwater a fictional woman named Catherine Prior had been murdered. Ten contestants from the British public were set the challenge of becoming investigators and finding the killer. The investigators were led by Bob Taylor, known as the
Chief Investigator or
Chief, who was in real life a retired
Detective Chief Superintendent from the
West Yorkshire Police. The people from the town, played by actors, formed the suspects, some of whom later became victims. At the beginning of each episode, one investigator would be appointed as the
Lead Investigator, who would have specific responsibilities and powers. The investigators would be split into teams by the Lead Investigator, and sent down different lines of inquiry determined by the Chief. These lines of inquiry would involve hidden tests, which the teams would either pass or fail as judged by the Chief.
The Killer's Game At some point during the investigation days in each episode, the killer would leave some form of message showcasing two locations, usually accompanied by the taunting words 'coming out to play?'. This signalled the start of each episode's elimination segment,
The Killers Game. The investigators were then passed or failed on their lines of enquiry and those who failed were put up for a group vote. Every investigator except the lead investigator could vote and the investigator with the most votes would be chosen as the first person to play the "Game" The Lead Investigator would then choose any investigator to be the second person for the Killer's Game. The two chosen investigators pick from two envelopes to decide who will go to either of the two locations given, for example the first locations for the show were "The Old Oaks" and "The Power Museum". "The Chief" then says to the players that they have one hour to pack their bags and get ready to play the "Killer's Game". In Episode 9, as the finale episode, two killer games were played. The game with the final three had a different approach to the selection process. The Chief decided that the investigators who failed their enquiries the most would play the "Killer's Game". In the Killer's Game, the two selected investigators would be sent to two different remote locations completely alone, with their movements recorded only by a head-mounted camera and a torch, they also had to follow a map to where the "clue" would be located. One of the chosen investigators would discover an important clue that would help solve the mystery, whereas the other investigator would be eliminated from the show by being "murdered by the killer." The survivor of the two came through the doors at the entrance, notifying that he or she chose correctly and would continue on. The eliminated contestant would choose the Lead Investigator for the next episode, by means of a pre-recorded "last will and testament". == Story ==