On a rainy night in 1953 Britain, Mr. Magpie is trying to figure out a way to make ends meet at his electronic store. In the background, a newscaster concludes the day on the television
At another home, Mr. Connolly arrives home and his son Tommy asks him if they can get a television. His father vaguely promises that they'll get one and leaves. Tommy's grandmother warns that rumor has it that televisions dissolve brains.
On the roof of Magpie Electronics, a lightning bolt strikes the TV aerial. The television turns on by itself and the newscaster talks directly to Magpie by name. She assures him it isn't a dream and then fires blasts of red electricity out of the screen and into his face, while she laughs maniacally.
Sometime later, The TARDIS lands nearby and Rose wonders why they didn't make it to Las Vegas. The Doctor thinks they're in New York City and rides out on his scooter and invites the Rose to hop on and drive to the studio for the Beetles' first appearance. They quickly realize they're in London again, and its decorated with numerous flags.
Mr. Connolly and his wife Rita and son are watching their new TV and Mr. Connolly raves about it. Rita refuses to smiles and says it's been terrible since they got the television. They hear a banging noise upstairs and Rita says that Grandma is hungry.
As they walk down the street, the Doctor and Rose meet Magpie as he unloads new televisions. He explains that the flags are for the coronation of Queen Elizabeth II, while Rose notices that there are new TV aerials on all of the houses. The Doctor is impressed with the post-war era, but they're interrupted when two men haul a woman in a bag out of her home and into Magpie's van, while her husband looks on, satisfied. The Connollys come out to see what the noise is, and Tommy comments that it's been happening a lot and people are turning into monsters. Mr. Connolly calls him back into the house. Meanwhile, the Doctor and Rose drive after Magpie's van but Magpie has set up a plan to evade any pursuers. Rose suggests they talk to the neighbors.
In his electronic shop, Magpie puts a device on a bank of televisions which all broadcast the picture of the woman. He says that he's being burned up inside, and she says she may release him if he's a good boy. However, she tells him that his world is forging into a new era and is very busy, and says that the time will soon come.
Tommy walks up the stairs as Grandma pounds again. He prepares to unlock the door but Mr. Connolly comes up behind him and asks for the key. Once he has it, he takes Tommy downstairs and berates the boy in front of Rita. Tommy objects to him locking up Grandma, and Connolly tells him that Tommy will stay and work in the business instead of going to college. When Rita tries to protest, he verbally abuses her as well. There's a ring at the door. When Mr. Connolly answers it, he finds the Doctor and Rose at his doorstep. The Doctor poses as an inspector and barges into the house, then browbeats Mr. Connolly into doing his own work and put up the celebration flags. They then settle in to watch television and convince Rita and Tommy to tell them what's wrong. Rita starts to explain and Mr. Connolly objects. The Doctor shouts him down and orders him to explain, and Mr. Connolly admits that Grandma never stops knocking. Tommy explains that they've heard stories of people changing, and mysterious men come to take away those that are transformed.
Tommy takes Rose and the Doctor up to see Grandma, and they discover that she has no face. The Doctor scans her and discovers that her brain has been wiped clean. The mysterious men arrive and barge into the house. They knock the Doctor aside, bundle up Grandma with Mr. Connolly's assistance, and leave. The Doctor runs downstairs after them and Rose follows, but notices red electricity flowing from the television. She approaches it while the Doctor drives off in approach. She examines the television and finds a Magpie label on the back. Mr. Connolly orders her out and she leaves.
The Doctor follows the abductors' car but loses them the same way he did earlier with Magpie and his men. The Doctor goes in on foot to investigate the adjacent warehouse and finds more faceless individuals, held as prisoners. They start to attack the Doctor but the abductors enter the cage and hustle the Doctor out for interrogation.
Rose goes to Magpie's shop and asks to buy a television. He tells her to come back tomorrow on the day of the Coronation, but she notes that he'll be closed that day. Rose wonders why he's all but giving them away. The newscaster appears on the screen and chants "Hungry!" repeatedly, and Magpie tells Rose to leave right now. He boasts that 20 million people will be watching the Coronation, and insists that he has to close. Rose tells him that something is happening and his televisions are responsible, He's relieved that he's been found out and says that he's only been doing it to get peace from the newscaster. The newscaster talks to Rose and says that she's hungry, and then fires bursts of electricity at Rose. Her face is pulled off into the screen while Magpie apologizes, warning things will never be the same.
The abductors interrogate the Doctor, who realizes that their police officers. Their leader, Detective Inspector Bishop, tries to get answers from the Doctor. However, the Doctor points out that all that Bishop is doing is hiding away the victims. The inspector admits that it's beyond his ability to deal with and he has no idea what's going on. The Doctor offers his assistance and tells Bishop to start from the beginning. The inspector explains that the victims first started up a month ago and many of them are near the Connolly house. Bishop's men arrive with another victim and the Doctor realizes that it's Rose. Her facing is missing the same as the other victims. The Doctor vows to find the persons responsible no matter what and leaves.
Across London, the sun rises and people prepare for the Coronation. Mr. Connolly has neighbors and relatives over, including Aunt Betty, and tells Rita to smile and behave herself. They all sit down to watch the television and Rita makes excuses for the fact that Grandma is absent. The doorbell rings and the Tommy goes to answer it. Bishop and the Doctor are there, and the Doctor tells Tommy to describe everything that happened. Mr. Connolly comes out and tells them to leave, and insists that it matters what people think. Tommy asks him if that's why he ratted on Grandma to the police, and then accuses him of becoming the very fascist that he fought against in the war. When Rita comes out and asks for the truth, Mr. Connolly insists that he had to inform on them. Rita wonders if he did it for them, or for us, and tells Tommy to do what he can for with the Doctor. She goes inside and locks the door, leaving Mr. Connolly outside and alone.
Tommy talks about how Grandma was watching television the night she was transformed, and that Magpie sold them the television. They go to the shop and the Doctor demands that Magpie show himself. He finds advanced technology, a portable television, and detects another power source. The faces of the victims appears on the TV screens, all silently crying out. One of them is Grandma, and another one is Rose. The Doctor promises her that he's on his way. Magpie comes in and the Doctor demands to know who is in charge. The Wire image appears on the screen and Magpie introduces her as his new friend. She explains that she is the Wire and will feast on them all, and then regain the corporeal body that her people deprived her of. She fled across the star when her people destroyed her form, but now she plans to leave the television. The Doctor explains that it feeds on the electrical impulses of the brain, stripping them of their identity and their faces. Magpie explains that the Wire has agreed to release him when she manifests, and the Wire boasts of its crowning glory. The Doctor realizes that the Wire isn't strong enough yet and it needs the portable television. It will transform a receiver into a transmitter. She tells them to relax because there's nothing they can do, and then releases energy onto all of them. However, when she realizes the Doctor has his sonic screwdriver, she withdraws, transmits herself into the portable TV, and tells Magpie to take her to her victory.
The Doctor recovers and discovers that Bishop has been transformed, but Tommy escaped the brunt of the Wire's attack. They figure the Wire will harvest millions and it will head for the biggest transmitter in London. The Doctor goes to get some parts from Magpie's shop, while Magpie drives to the transmitter. Once he has what he needs, the Doctor and Tommy head for the transmitter as well.
Magpie arrives at the transmitter and climbs toward the top. He begs the Wire not to make him do it, but it informs him that the time is at hand. Clutching at his head, Magpie continues to climb.
The Doctor and Tommy get to the transmitter and set up the equipment in the control room. Once everything is in place, the Doctor tells Tommy to continue no matter what and climbs the transmitter tower. Magpie hooks the portable TV up to the transmitter and the red lightning spreads out across London. Everyone viewing a television is drained by the energy.
The Doctor, carrying a spool of wire, warns that he won't let the Wire win. Magpie begs the Wire to stop, saying it promised him peace. It gives him peace and dissolves him with a burst of electricity. Realizing the Wire has overextended itself by destroying Magpie, the Doctor grabs the portable TV, his rubber soles protecting him from the energy. He plugs in his wire to the portable TV but nothing happens. Below, a wire has snapped. Tommy hastily resolders it and the lightning draws back into the portable TV. The viewers return to normal with no memory of what happened. The Wire screams in agony and the portable TV screen turns off.
The prisoners in the warehouse, including Rose, are restored to normal upon the Wire's defeat. Meanwhile, the Doctor tells Tommy that he turned the receiver into a transmitter and recorded the Wire on home video. The coronation continues and throughout London, everyone watches in satisfaction.
The Doctor and Tommy go to the warehouse, and Tommy is reunited with Grandma. Rose finds the Doctor and they share a hug.
Rita tells her husband to get out of her house. Mr. Connolly takes his bag and leaves.
As everyone gathers in the streets, Rose suggests that they join in the crowds at the coronation, but the Doctor is happy to see the people celebrating. The Doctor assures Rose that he'll tape over the recording of the Wire, and leaves his scooter to Tommy. As they watch Mr. Connolly leave, Tommy is satisfied that he'll be out of his life. Rose tells him to go after his father, because Mr. Connolly is his father and that Tommy is clever enough to make things up. The boy goes after his father and the two walk off, together.