This episode begins with a flashback from twenty years ago. McNair is in a cage and in walks Herrick. It seems that Herrick put him in a cage with a werewolf, and somehow not only did McNair survive, he killed the werewolf. Herrick begins to ask questions about his life and McNair admits that he did not escape unharmed and that the werewolf scratched him. Herrick begins to cackle because he realizes that McNair is now a werewolf.
In the present day, Mitchell is trying to convince Annie that what happened in the tube is vampire business. He says that if they arrest Daisy and take her photograph that she will be revealed to the world. He points out harmful this is to humans. Annie says that vampires have been arrested in the past, but Mitchell responds that they used to have an infrastructure to get away with it. Annie is determined that Daisy not get away with what she has done.
Back at the police station, Nancy is telling her superior that Mitchell has told her all about Daisy. What they don't know is that Annie is in the room with them listening to every word that they say. When she looked up Daisy, Nancy learned that she died in an air raid in 1941. Nancy tells him that she found Mitchell's scrap book and this shocks Annie. Her superior is more than willing to say that Mitchell is just sick. He says that they have a long list of suspects with violent histories, and that if they don't make an arrest this week that the entire team will be changed. He believes that the clippings and talk of ex girlfriends is nothing more than gossip. He goes onto say that Nancy doesn't even have a fingerprint or anything that passes for proof, and demands that she stop pursuing it.
Back at the house, Nina is shaving Herrick and he asks her if she trusts Mitchell. "If Mitchell told me the sky was blue", she says. "I would have to go outside to check." Herrick tells her that Mitchell told him that he is a vampire and that the people who tormented him said so as well. He says that when Nancy came to the house that he could hear her blood throbbing through her veins, but he doesn't with Nina, George or Annie. Nina tells him that whatever he is that he can overcome it. Herrick wonders if he is the victim of a conspiracy to drive him mad. She tells him that he is not going mad and that he needs to stay separate - stay appalled. Herrick admits to Nina that he showed Nancy Mitchell's scrapbook and says, "let justice be done."
McNair and Tom show up at the house because McNair has been hurt. He notices the pinups that Annie has on the wall. McNair says that he was injured fighting vampires and that he and Tom killed four. McNair says that he is surprised that they have not shown up for Nina and George yet, and suggests that they are off limits because of Mitchell. McNair goes on to say that he knows something has changed in the house.
In the kitchen, George tells Tom that at 19 that he shouldn't be killing vampires out of the back of a camper van. Tom says that he doesn't have a choice. George offers to let Tom stay with them, but Tom says that McNair would never allow that. When Tom and George go back into the living room, McNair announces that they are going to stay for awhile to rest his leg. This makes me wonder if he can smell Herrick upstairs. When George mentions that it's a full moon, McNair suggests changing in the basement and points out that it is probably not a good idea to run around the forest in this state. He suggests that they stay for a few days and that Tom could watch cartoons, and that maybe George would take him for a pint. Is anyone else confused by this? He is 19 and a hook to stay in the house is to watch cartoons and drink beer?
Back at the station, Annie and Nancy are in separate stalls. Annie talks herself into believing that the reason that Mitchell has the scrapbook is that he is investigating the murders as well, because he told her that vampires take care of this sorts of things themselves. She says to Nancy, "never mind what the shouty man said. Mitchell can lead us to Daisy and there's something bigger at stake her." This had me wondering if Annie forgot completely that she is a ghost, and that Nancy cannot hear her. Nancy leaves the stall and walks up to the mirror and announces, "John Mitchell, I'm coming to get you."
When Mitchell comes in he sees McNair and Tom. George tells him that they have guests and Mitchell says that it's fine and walks upstairs to see Herrick. He demands to know how Herrick survived the werewolf attack. He grabs Herrick and says, "I haven't got the time for this. The old Herrick has got the answers so we need to find him now." Once again Herrick denies that he knows what Mitchell is talking about and so Mitchell leaves the room.
Downstairs, Annie tells George and Nina that Daisy killed all of the people on the tube. Nina of course asks for proof and Annie tells her that he has a scrapbook and has been investigating the murders as well. Nina once again expresses surprise that Mitchell is not guilty. George admits that he met both Daisy and her husband and that it makes sense. Annie tells them that Nancy is on her way there.
Nancy shows up and asks Mitchell why he has clippings of the box tunnel 20 if he has no connection to the case. He tells her that there was this guy Graham who put it altogether, and he thought that Mitchell would be impressed. Nancy says that she knows that Mitchell is lying to her and asks to speak to Uncle Billy again. When Mitchell says that he doesn't think that this is a good idea, she says, "I don't bite." Mitchell says okay and goes up to see Herrick.
Mitchell tells Herrick that the first time that they met they were soldiers. He tells him that in war, men have to do things that they've never dreamed of, but in a war these things can be heroic. Herrick says that we are not war and Mitchell counters saying that they are at war - a secret war. He points out that sometimes they are asked to do things that seem bad, but they are not bad but brave. Mitchell says that Herrick has to brave enough to let nature takes its course.
When Mitchell walks out of the room, Annie is waiting for him. He wants to know what Annie was thinking bringing Nancy back to the house and Annie tells him that Nancy thinks that he is the murderer. She suggests that he just give her Daisy. He again asks why she cannot understand that if he gives Nancy Daisy that everything will end. Annie counters by pointing out that the same thing will happen if he gets arrested. Mitchell says that he won't allow this to happen, and that he will deal with this.
Downstairs, Nina admits to Nancy that she was the one who reported him and that she has changed her mind. When Nancy asks why, Nina brings up Daisy. Nancy asks why they have given her "the name of someone who died before the cocking coronation." Nancy goes on to say that something is going on in the house and she wants to know why everyone thinks that they can lie to her. Mitchell comes downstairs and says that Herrick is waiting for her.
When Nancy enters the room, all Herrick can hear is the rush of her blood, as she tries to ask him about Mitchell. Just before Herrick is about to strike, Mitchell enters the room and pulls Nancy out. On her way down the stairs, Nancy grabs the glass with Mitchell's fingerprints on them.
As soon as Nancy leaves, George, Nina and Tom prepare to leave for the change. As soon as they leave, McNair gets up and starts walking around. It seems his injury is not nearly as bad as he has been pretending. He sits down and writes a note.
Annie goes back to following Nancy and they end up at the train where the murders happened. Cooper, Nancy's superior is waiting for her and says that he got the results on the prints. Apparently, they found Mitchell's prints at a murder from the 60's, as well as in the box tunnel 20. He says that Mitchell's prints were everywhere, including in the blood, which makes them postmortem. Cooper announces that Mitchell is indeed the murderer. Annie begins to cry and sits down. Cooper asks what other evidence she has, and Nancy tells him about the burned scrapbook. Cooper suddenly punches Nancy.
Mitchell comes in and believes that the house is empty. He grabs a beer saying, "prophesy my ass." He has no idea that McNair is in the house. McNair slowly slips up the stairs.
Back at the scene, Cooper says, "Mitchell couldn't have done more to implicate himself than if he left a note. Mitchell was never really a team player but arresting him can't happen." Nancy kicks Cooper's leg in desperation. He calls out asking if Annie is still there and when Nancy asks what he is talking about, he tells her that she has a ghost following her around, and that it probably had something to do with Mitchell. When Cooper gets his hands on her, he tells her that he won't kill her, but suggests that he intends to make her a vampire. Annie sneaks up behind him and stakes him saying that Nancy is not interested.
Upstairs, McNair bursts into Herrick's room and says, "as long as I live, I will never forget that scent." Herrick responds, "I assume that you are another victim of some barbarity I am supposed to have committed." Herrick tells him that Mitchell is keen on keeping him alive, and that if McNair attempts anything that he will call for him. It seems that this has been McNair's plan all along. He shows him the necklace of teeth that he has collected from vampires. Herrick tries again saying, "the man you knew, is not the man before you now." McNair tells him that vampires don't reform. Downstairs Mitchell pronounces himself safe and leaves. McNair completes the change and attacks Herrick.
The next morning, Nina and George go to the hospital for a check up. The nurse takes one look at Nina and suggests that she is much further along than she thinks. Mitchell returns home and run upstairs to check on Herrick who is on the floor. Herrick tells him that McNair became a monster and attacked him. Outside, Nancy calls for backup saying that she is going to arrest Mitchell for the box20 murders, and has reason to believe that he is armed.
Downstairs, Annie is waiting when Mitchell comes down. She simply tells him that she knows. He asks how she found out and she says, "Nancy and a vampire." Annie asks if Daisy was involved and he says yes, but that it was his idea. She tells him that this was probably the first honest thing that he has said to her in months. Annie demands that he turn himself in to give the families some peace, but Mitchell says that he cannot, because everything will be torn apart. Annie promises that she will stay with him no matter where they take him, or what they do to him. She promises him that he won't be alone. Mitchell says that it's not about fear and punishment, and that he wants to be punished. The police knock at the door and he asks for her help and says that if they arrest him that he will have to kill them all. Annie begs him again to turn himself in, as the police burst into the house and surround him with guns. Annie begs him to let this happen and to stop the killing, and so he surrenders to the police. Nancy reads him his rights and he says to her, "you've no idea what you've done."
Nancy goes back in the house and up to the attic to get "uncle Billy." When she walks into the room she sees McNair's body and Herrick jumps out of the shadows and attacks her. When Mitchell arrives at the police station, he again begs to be let go saying that they are not ready for this. He is asked his date of birth and says, July 29, 1893 and begs again to be let go. He says, "it can't happen like this, not in Wales." In frustration, the sergeant asks where Nancy is.
Back at the house, Herrick is covered in Nancy's blood. He looks at McNair a touch confused. George and Nina are on their way back to the house and discussing why she is so much further along. George tells her that wolf gestation is a lot shorter than human gestation. When they arrive at the house, they see the police tape. Nina realizes instantly that they've come for Mitchell. Nina admits to George that she was the one who reported Mitchell to the police. Nina says that she didn't say anything because she knew that George would take his side and try to cover for him. George says that he is going to the police station and when Nina offers to come along, George says that she is to stay there and that he does not want her anywhere near him.
At the station, they fingerprint Mitchell and take a sample of DNA from his mouth as he struggles. The sergeant walks in and announces that no one is answering their radios at the house. Back at the house, Nina walks into the house announcing her presence and gets no answer. What she does not know is that Herrick has already killed everyone. She goes to the sink for a drink of water, and Herrick sneaks up behind her wearing a police uniform. He tells her that George tore him limb from limb, and then places his hand over her mouth so she cannot scream. He tells her that the pain was incredible and now he wants George to suffer, and that the best way to do that is to kill her. Because Nina was the only one in the house who was kind to him, even as everyone in the house wanted him dead he decides that his quarrel is not with her. Herrick lets her go and walks out of the room. He walks in moments later saying that people will think that he has gone soft, and he stabs Nina.
I have to say that this was the most exciting episode this season. I loved the scene between Mitchell and Annie where he admits his guilt, though I do find Annie's continued insistence that he turn himself in ridiculous. I knew from the beginning that McNair was up to absolutely no good, but watching as he sat back patiently helped to build the tension. Because I am watching this a full year after this season aired, I have a pretty good idea of where the next episode is going, but I have found that this has not stalled my enjoyment of it in the least.