A black man arriving at Heathrow from Brazil is stopped when an official notices blood coming from his ear. He is taken for a medical examination and the woman with him makes an urgent phone call. The doctor finds he is wearing a bandage near his neck and underneath is a bloody wound.
Michael shows up at Frances as she's leaving for work. Jacob has been to Michael's old school and to his parents. Michael is worried that when Jacob attracts unwanted attention, Kirsty will be dragged in as well. He's afraid that if he tries to warn Kirsty off, his people will find out. He asks Frances to talk to Kirsty but she refuses, Kirsty's a grown woman.
Angie examines the man from the airport and reports to Harman that the wound is Code V. It's visible because he has some sort of hemorrhagic fever. It causes bleeding from a weakness in the skin, visible or otherwise. His sister's been nursing him but she asked specifically for Dr March by name. Michael meets Vaughan at the airport to go through the man's luggage. Harman and Angie go to interview the sister and realize that she wasn't looking for Angie, but her husband Robert March. Her brother suffers from sickle cell anemia. His doctors gave Robert's name and Angie tells her he's been dead for six years.
Michael and Vaughan find medication in the suitcase. Vaughan knows about sickle cell as he was tested for it in the army. It turns round blood cells into a sickle shape which get stuck in the blood vessels, blocking the flow. When Michael queries how Vaughan knows so much about it, Vaughan explains that Robert March was working on it before he was turned. Angie gets frustrated with the sister, Maria, her brother doesn't have sickle cell. Maria says it is because of the transfusions. Angie insists sickle cell isn't curable with transfusions. When Angie gets agitated, Harman makes Angie leave.
Michael and Vaughan question the airline staff and though there was nothing odd about the flight itself, the plane did take cargo on board. Five crates. They get to the cargo area as the van pulls out. Michael runs to his car and takes off in pursuit. Vaughan sees they left one box behind and he orders it pulled into the sun. It is marked 'medical supplies'. Once opened, there is a six foot metal container inside.
Harman continues questioning Maria. Aguinaldo's doctors said Dr March wouldn't see them, that he doesn't do charity. They decided to come anyway, without trying to contact him. Angie comes in to report Aguinaldo is stable but Harman says he'd prefer if Angie stayed with him. She reluctantly leaves. Vaughan has the container x-rayed. The manifest says it's organs for transplant. Vaughan pulls his gun, ordering everyone out. He hesitates when he sees there is a timer on the container, counting down the hours till sunset. Michael follows the truck, with helicopter escort, a van following him with armed men.
Angie puts Aguinaldo under ultraviolet and notes there are multiple bite marks over his chest too. Vaughan returns the unopened container to the office, which they place in a room with armed guards. Harman intends to question whoever is inside. Frances phones to tell Michael that she stopped by Kirsty's. Kirsty quit her job last week, Jacob quit his three weeks before that. She's not answering her phone and both their cars are outside her house. Frances mentions the curtains are drawn in the middle of the afternoon. Michael asks her to leave a note giving Michael's fax number. Michael continues to follow the van with his team.
Vaughan checks in with Angie. Though his medical records say he's got the worst type of sickle cell – frequent and severe – there's no indication of it under the microscope and no signs of hemorrhagic fever. Frances leaves a note under Kirsty's door and Jacob goes to get it. When he reads Michael's name on it, he smiles.
Michael watches the driver stop to make a phone call and Michael comes up behind him, pretending to count change for the phone. When the driver sees him, he quickly walks back to his van. Maria gets increasingly agitated, insisting on seeing Angie, saying there is only one way to help and that she must talk to Angie about her husband. She accidentally calls Harman a priest. When Harman says she'll get nowhere near Angie, she asks if she's free to go which she is. Harman tells Vaughan to escort her to her hotel. She says she wants to pray and goes to the dock, making a boat to put in the water, a way of praying in her religion. She says Robert March can be saved. Maria knows far more than she was letting on, she insists they just want to talk to Angie, that they want peace.
Michael reports to Harman that the driver recognized him and thinks this is a waste of time. Angie says the wounds are not from feeding, more as if they were tasting him. Michael is now sure this is a diversion and Harman agrees to let him pull the van over. Vaughan informs Maria that the 'doctors' were spotted at the airport, one of them is under lock and key and the others are about to be picked up, so she better tell him what she knows. Maria insists Angie can have Robert back. Whatever they were doing to Aguinaldo wasn't for his benefit, he was an experiment, nothing more. She protests that they gave him six months of peace, no pain, but Vaughan points out look at him now.
The van is pulled over, the drivers arrested. Maria takes Vaughan to a warehouse where she had intended to bring her brother and Angie. Michael finds the van is empty. A guard comes up behind Vaughan and knocks him out. He demands to know from Maria where Angie is. Michael interrogates one of the drivers, how'd they do it? The containers were never on the van, they were diverted before Michael and Vaughan arrived. Vaughan wakes up inside the large, empty, locked warehouse and sees the missing four containers, with five minutes before they open. Michael phones Vaughan, in the helicopter, he has the location from the driver but is twenty minutes away. Vaughan tells him about the containers. Michael asks if he can get out, he can't and tells Michael so.
Harman and Angie wait for the fifth container to open. Vaughan phones Angie but can't think of anything to say and hangs up. Vaughan pulls his gun and puts the barrel under his chin. Michael, still fifteen minutes away, anxiously toys with his gun. Vaughan aims the gun instead at the containers and thinks of a plan. He drags a container to the locked entrance and with a minute left, short circuits the timer to make it open prematurely. When it opens, he kills the vampire which explodes, leaving a hole in the door.
Harman and Angie watch the vampire who climbs out of their container. His first words are that he is a friend of her husband's. Michael arrives to find one container exploded and the other three empty. Vaughan walks up behind Michael who immediately wonders if he's been turned but he hasn't, for which they are both very relieved.
The vampire shows little interest in Harman, focusing on Angie instead. Though he is facing a mirror, in which he casts no reflection, he seems to know where Harman and Angie are. He says that he never knew Robert while he was alive but impressed all of them with his intellect. Robert's sole condition for being taken was that he could have Angie and their children too. Robert never stopped loving her. What a pity they, Robert and their five year old daughter, never got the chance to talk to her before they were executed. Angie walks out. The vampire knows Angie has left and refuses to talk to Harman.
Maria is found, she committed suicide in the river. Michael asks how Vaughan met the vampires for the first time. During the Gulf war, he was with his squad and when he saw bullets couldn't kill them, he ran. The rest of his squad stood their ground and died. By the time the vampires caught up to Vaughan, the sun was coming up and they couldn't finish the job.
Harman finds Angie in the lab, giving Aguinaldo a transfusion. The problem wasn't the transfusions the vampires were giving him, but the blood they were transfusion him with. She realized when she saw the blood they put into him was perfect, no abnormalities – the blood is synthetic. Artificial blood has been used for short term use, after operations, just for carrying oxygen but this is far more advanced. They were using a human subject because if he could survive with synthetic blood, so could they. That was what the bite marks were, they were tasting it. They need Robert to perfect it. Angie suggests maybe they are looking for peace but Harman refuses to consider it.
Returning to the office, Michael offers to buy Vaughan a drink. He declines, wanting to check on Angie. When Michael asks if Vaughan will tell her about his day, he says no – and neither will Michael. Vaughan thanks Michael then brushing off his clothes, goes in to see Angie. Angie released Aguinaldo, he knows nothing, he believes it was an experiment with severe side-effects. With the real blood transfusion, he's back to normal, back to sickle cell. Angie knows Vaughan had a close call but not the details. She invites him for coffee at her house. He agrees.
Michael returns home and finds no messages, but finds a fax from Kirsty agreeing to meet him. He changes, checking his hair in the mirror then rushes out… forgetting the camera for his gun on the bed. Angie fixes Vaughan a drink, tension in the air, and abruptly asks what Maria said about Robert. He says nothing but admits she said Angie could have Robert back. He told Maria that when you're dead, you're dead, that they need to move on. Realizing Angie's not ready for that yet, he finishes his drink, kisses the top of her head and leaves.
Michael meets Kirsty. They hug and sit down. She asks if he's risking his job seeing her but he says it's not him who's at risk. She has accepted she'll never know the truth about Jack and has been punishing Michael for no reason, except that he was there. Jack hurt them both. Michael asks about Jacob. She says he latched onto her and that's he's been saying things about Michael, but she doesn't believe them and she's not going to ask. She insists she's not sleeping with him and realizes Michael's been spying on her. She accuses him of being jealous, which he denies, saying it's stupid. When she asks if it's that stupid, staring into his eyes, he goes cold. Suddenly wary, he asks why she isn't drinking her wine. She says she better not. He gets up as if going to the bathroom and walks away from her, shaken. He goes into the bathroom, leaning against the door then puts his gun on the counter and washes his face. He reaches under his jacket for the camera, realizing he left it at home. In tears, he wipes his face with his arm then uses the butt of his gun to smash the mirror. He re-enters the bar and tries to use a piece of mirror to see if Kirsty has a reflection, holding it so tightly he's bleeding. When he can't see her, he panics, reaching for his gun and is tackled by security who force him face down on the floor. Kirsty turns at the commotion and sees the gun in Michael's hand and the look on his face. Terrified, she runs out… and Michael sees her reflection in the mirror at the door.