Episode list

Long, long ago in Middleford, a small, safe, English suburban town, a stranger arrived with a secret -a secret that would wreak havoc and transform Middleford from a peaceful, domestic haven into a town of terror. The story begins on Bonfire Night 1983, as the ordinary citizens of Middleford go about their ordinary lives: Copper Wendy pops round the butcher's for some sausages and American beef burgers. Forensic scientist Martin shows newcomer Shauna around his laboratory. Wendy's boyfriend Colin tells his mate Anthony about aliens and gives him a copy of Invasion of the Killer Crabs. Later, Colin and Wendy quarrel while shopping for their Guy Fawkes sausage sizzle. Martin attends an Anti-American action group, where attendees are warned of fast food restaurants and American cultural imperialism. At the party, Colin grouses to Wendy about her inviting all of her boring, aggressive copper friends. Anthony tries to chat up a cornered Shauna. Driving up to the Close, Martin spots raw organs dripping from a sign. An unseen stranger lurks outside Wendy's flat. Martin looks for girlfriend Shirley, who is missing with his flatmate Graham. Colin storms out of Wendy's just as the stranger, who bears an uncanny resemblance to Donald Sutherland, arrives to use her telephone. Martin discovers a mysterious attaché case. Wendy doesn't realize that the American stranger is wearing a blood-stained shirt.

The stranger hides his bloody clothes from Wendy. Martin is called in to work for a disemboweling and stashes the mysterious case in his fridge. Wendy invites the stranger to spend the night. Martin learns of the brutal death of Wendy's butcher. The stranger admits to Wendy that he's suffering from amnesia and speculates that something's wrong in Middleford. Martin makes a shocking discovery in Graham's bedroom. The stranger remembers that he's a writer. Colin is attacked by his pet goldfish. The stranger recoils in horror at Wendy's screwdriver. Wendy tells her copper friend Julie about her new American friend, and then she's sent to investigate a husband who's been sucked down a street drain. Martin makes a discovery the laboratory. Colin lectures Anthony about the allegories of science fiction. Martin tries to open the attaché case. While questioning Martin about the lack of children in Middleford, Wendy's electricity goes out. Wendy discovers the stranger's bloodied shirt, then he appears at her door.

Martin's tins of crab meat have been opened from the inside. Colin and Wendy think the stranger may be responsible for exploding the butcher, but Martin dismisses Middleford's strange occurrences as unknown radiation. The sky over Middleford turns red. The stranger insists he can't remember if he was involved in the butcher's death. Martin tells Colin that Wendy never liked him. Wendy and the stranger's intimate moment is interrupted by Colin, who warns Wendy she's in danger. Colin notices that the stranger doesn't bleed. Martin confides in Wendy about a massive cover-up involving the dead butcher and high levels of unknown radiation. No one believes Colin's story when he's attacked by ice in Wendy's fridge. Mrs. Maynard, Wendy's neighbor, pops round to tell Wendy that her budgie exploded, and she corroborates Colin's story. Martin suspects Americans are responsible for unknown radiation in Middleford. Food and appliances attack everyone in Wendy's flat, and she's swallowed by the sofa. Escaping by car during a storm, Colin and Martin are horrified to see that it's raining liver.

News presenters attribute the strange occurrences in Middleford to meteorologic conditions. Wendy escapes from the sofa, while the stranger regains his memory. Martin's professor warns him about analyzing samples of liver, prawns, and a rubber plant. Colin and Anthony investigate recurrent themes in science fiction novels. Wendy and the stranger profess their love for one another. Colin tries to convince Martin to leave Middleford. The stranger implores Wendy to do something vital for him. American GIs announce in the pub that no one can leave Middleford. Martin discovers that the attaché case is missing. Just as the stranger is about to open the case and reveal all to Wendy, American GIs arrive. In the sewers under Middleford, a giant prawn pursues Colin. Martin watches in horror and disbelief as the professor's head explodes in the laboratory.

Shauna finds Martin covered in the professor's brain matter. The stranger and Wendy are entranced by the contents of the case. Shauna's head explodes all over Martin. In an American accent, Wendy tells the stranger she must go to Martin. Colin escapes the sewer, finds Middleford in chaos, and is attacked by a zombie. Mrs. Maynard is growing hair on her hands and reading Communist books. Martin advises Wendy that the stranger is a psychic assassin sent by the CIA. Later, Wendy returns to Joe, the stranger who is actually her husband. Wendy wants to leave for "home", but Joe insists they stay because he's responsible for what's happening in Middleford, and it's going to get much worse. While Martin eavesdrops, Joe tells Wendy that he wants to redeem himself by saving the wretched people of Middleford. Colin learns from Martin about the stranger's mind-hold on Wendy, who has gone with him to the American military base. Colin shows a glimmer of recognition at the mention of Dr. Oblinski, a man theorized to be behind everything that's happening. While arguing over the case, Colin and Martin's car crashes. American GIs capture Joe and Wendy. Colin opens the attaché case. Martin awakens from the crash to find Colin speaking with an American accent. Colin reveals that the aliens have come from planet Earth.

Colin reveals his true identity to Martin, who learns the shocking truth about Middleford. Professor Oblinski reveals that he must deactivate the central computer to stop Armageddon in Middleford. Martin finally finds Graham and Shirley, but it's too late. Wendy's suffering from a headache that threatens to explode her head. A flashback recounts how Wendy and Martin came to be in Middleford with their memory erased. Martin decides to go into the final frontier past where Middleford ends. Professor Oblinski discovers the location of the central computer but is running out of time. Sarge and Julie, now zombies, attack Joe and Wendy in the supermarket. Later, their attempt to escape Middleford is thwarted by Martin. Joe realizes what he has to do to stop the destruction. Professor Oblinski is captured, but curious new arrivals may continue the story of Middleford.