Synopsis In the near future, global warming has caused vampires to come out of the shadows and attempt to retake the earth. 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. Over the course of the series, Michael and the organization investigate vampire-related activity, often involving medical experimentation. Individual cases involve a woman who may be pregnant with a vampire fetus, a vampire test subject with synthetic blood, and the outbreak of a disease related to vampirism. The vampires are organized, and appear to be moving toward a common goal; the organization must determine what their agenda is. Living and working in the shadows takes a personal toll on the organization's agents: Michael's relationship with Jack's fiancée (Colette Brown) is threatened by his need to hide the truth from her; Angie Marsh (Susannah Harker) must come to terms with the loss of her husband, who was killed by the organization after becoming a vampire; Fr. Pearse Harman (Philip Quast) is diagnosed with terminal cancer, but fears that leaving his post may doom the world to whatever fate the vampires have in store for it. The final episode reveals that the vampires' plan does not involve enslaving humanity as suspected. Instead, they plan to cause a nuclear winter, providing long-lasting darkness, and completely wiping out the threat of humanity with an engineered plague. Scientific advances made during their experiments will allow them to survive on synthetic blood and reproduce via live birth, eliminating the need for human victims.