When two men are discovered killed and mutilated, DCI Red Metcalfe (Ken Stott) is called to head the investigation. A brilliant detective, Red has a celebrated ability to get under the skin and into the minds of deranged killers he hunts.
He assembles a top team - bright newcomer Kate Beauchamp (Frances Grey), his protégé Jez Clifton (Jamie Draven) and Duncan Warren (Neil Dudgeon), a tough experienced copper whom he pipped for promotion. But there are no clues, no obvious motive and no evidence - except the way in which each victim is left with a silver spoon in his mouth in place of his tongue.
More corpses are discovered with horrific injuries, but as the body toll rises, the team are no nearer finding their prey. A bizarre pattern begins to emerge and Red takes the case personally.
He discovers that his brother Eric (Kieran O'Brien), a convicted murderer who hates Red for turning him in, has been released from prison. Desperate to make his peace, Red tries to visit him - and stumbles upon divine inspiration in murals on the walls of the local church.
The discovery that the killer is murdering people whose names and jobs match the 12 Apostles of Christ in exactly the way depicted in the Bible is a shock for DCI Red and his team.
They realise that the slaughters are committed on each Apostle's Saint's Day. But a massive operation to protect anyone who could be a potential target fails tragically.
Red sinks deeper into despair and his team begins to crack. Finally, a clue is found - a hair on the body of a victim and a witness who saw a policeman leaving the scene of the crime. Could the killer be on the inside?
An arrest is made but Red receives a parcel od silver coins, like those given to Judas, and fears that he might be the final victim. Red realises that he must confront a dark secret which he thought would never be discovered...