Detective Sergeant Michael Colefield (Jack Davenport) discovers that his best friend Jack (Stephen Moyer) has gone missing on the night before his wedding. Investigating Jack's disappearance leads Michael into the path of a secret paramilitary vampire-hunting organization supported by the British government and the Vatican. Michael learns that Jack has become a vampire. Michael remains devoted to his friend and abhors the brutal methods used by the organization's agents – including Vaughn Rice (Idris Elba) – until he realizes that Jack is lying about his situation and that the vampire hunters are correct in their assessment of the vampires. He allows himself to be recruited by the organization, but he hopes to find a middle ground.