In the ancient past, the enemies of Briton come together to fight an impossible opponent. They eventually win despite massive casualties, and split their opponent's vanquished body into three pieces and buried them at opposite ends of the world, while vowing that the burial sites would be forever guarded. The three leaders hide the pieces on Anuta Island in the South Pacific, in Siberia, and in Yorkshire, England. However, the leader traveling to Yorkshire was killed by bandits en route.
At an archaeological dig in the sewers beneath Sheffield Town Hall, Aaron and Lin work on New Years' Day. Aaron asks if they're going to talk about the kiss that happened between them, and Lin agrees. He wonders if it was good for her and they dance around rather it was romantic or not. They both admit that it was for them, and Aaron wonders what they do now. Lin suggests that once they're done, they plan a time to go out on a date. They find something beneath the corpse's hand and bag it, and Aaron suggests that the stories of the Battle of Hope Valley are true. In the bag, something glows.
On Anuta Island and Siberia, the modern-day guardians react as the ground shakes. They dig up the burial sites and watch as the pieces disappear in flashes of light.
At the dig site, a tentacled creature moves within the bag.
The TARDIS crew watch cosmic fireworks outside the vessel at the end of a tour of New Year's Eves, and the Doctor suggests that they do one more. An alarm comes in from Earth, and the Doctor realizes that something extraterrestrial is attempting a spatial shift. She takes the TARDIS to the location: Sheffield.
The creature in the bag drops to the floor, and Aaron and Lin hear the noise. Aaron notices that the bag is missing and Lin searches for it. She finds a tentacle creature clinging to the wall and reaches out to touch it. Meanwhile, the TARDIS materializes and the Doctor comes out and scans Aaron. The others come out and Aaron explains what they're doing, and calls to Lin. Lin comes over and takes them to the creature, but it's no longer there. The Doctor has Aaron get her something to put the residue in, and Lin explains where they are. Once they realize the creature could be in the sewer water, the Doctor sends Yasmin with them to make sure they get out to quarantine the area.
Outside, Aaron says that he'll call the authorities and they can talk more about their kiss. They walk away from each other, and Aaron texts Lin that he's thinking about her. In her car, Lin stares off into space.
The Doctor takes the TARDIS to Graham's house, and as they emerge the doorbell rings. Graham answers the door, slams it shut, and tells the others that it's a wrong number. The doorbell keeps ringing, and Ryan goes to answer it, ignoring Graham's objections. Yasmin asks Graham if everything's all right, and he says that it isn't. Meanwhile, Ryan discovers that the caller is his father, Aaron. He brings Aaron in and introduces everyone, and the Doctor tells Aaron that Ryan waited for him at Grace's funeral but Aaron never came. Aaron suggests that he and Ryan get coffee together, and Graham asks for a word alone with Aaron.
In the hallway, Graham asks Aaron why he's there. Aaron says that he was going to turn over a new leaf on New Year's Day, and Graham tells him to be gentle. When Aaron says that he just want to be a family with his son, Graham tells him that family isn't just a matter of DNA or a name, but about what they do. He says that Aaron hasn't done enough. Ryan joins them and calls Graham "Gramps", much to Aaron's surprise.
Lin drives home and goes to the bathroom, clearly ill. She removes her jacket, revealing the creature wrapped around her torso and neck. When Lin reaches for it, the creature tells her to stop. It says that it is her "pilot" and explains that it controls all of her motor functions. Lin tries to speak and the creature silences her, and says that she is its puppet now.
In the TARDIS, the Doctor scans the sample and realizes what it is. She tells Yasmin and Graham that it's the DNA of the most dangerous creature in the universe: a Dalek.
The Dalek creature has Lin put on a robe to cover it and then has her download everything on the Internet that must be destroyed. It warns that if she struggles then her friends will die at her hands. Lin asks what it wants, and the Dalek says that it will fulfill its purpose at last.
The Doctor tells Yasmin and Graham about the Daleks, and figures that the creature has become separated from its casing. She tells Graham that even if it's just one creature, it won't stop until it takes control of the planet. Yasmin calls Lin and gets her voice mail, and asks her to give her a call. The Doctor tries to work out how the Dalek is getting around.
Lin drives wildly down the road and the Dalek orders her to drive faster. A policeman pulls her over and the sergeant taps on the window. Lin rolls it down and tells the sergeant that he's an enemy of the Daleks, and the creature grabs him and pulls him into the car. His partner notices and runs over as the sergeant drops to the ground. The Dalek kills her as well and Lin drives off in the police car after taking the second officer's uniform.
At the diner, Aaron tries to sell the owner a microwave oven. The owner isn't interested, and Aaron goes back to the table where Ryan is waiting. Aaron says that he's going with a new job and suggests that he might go back to engineering. He asks Ryan how he's been doing, and Ryan tells him that it's about Aaron making things better. Ryan says that they're not at the point where he gives Aaron respect, and Aaron asks him what he wants his father to say. After a moment, Ryan tells him to apologize for messing up and not being good enough, and for making life hard for Ryan. Aaron tells Ryan that he's realized that there are thing that he's done in his life that he got wrong, and by the time he realized it, it was too late so he ran because he was too ashamed to make it right. Ryan tells him that he hid when he needed him, when his mother and grandmother died, and Aaron tells him that he's not hiding anymore.
Yasmin calls Mitch and the TARDIS follows the signal to his location. She takes him inside and the Doctor programs the TARDIS to scan for any trace of the Dalek DNA. The Doctor asks Mitch if he saw anything unusual at the dig site, and they go to Graham's house. Mitch says that a mythic creature was killed at the Battle of Hope Valley, cut into three pieces, and the pieces hidden all over the world. The Doctor figures the creature reassembled itself, and the UV light the archaeologists used brought the Dalek back to life. Yasmin says that Lin isn't replying, and the Doctor realizes that the Dalek has possessed Lin. They go back into the TARDIS and the Doctor connects Lin's phone to the TARDIS to locate her. The location matches the location of the Dalek DNA, and the Doctor tells Mitch that the Dalek is using Lin to move around.
Ryan and Aaron return to Graham's house, and Ryan enters the TARDIS, He says that he doesn't want Aaron in there, and the TARDIS console explodes. The Doctor realizes that it's a blast from the Dalek, sends Graham outside to get something she needs, and works out that it's a reconnaissance scout with special capabilities beyond those of a soldier Dalek.
Lin drives to her employer, MDZ, finds security guard Richard, and demands access to the archives. Richard says that he does, and the Dalek kills him and drags his body to the archive. After using Richard's palm print to gain access, Lin goes in, breaks open a case, and removes a Dalek blaster. As she loads the Dalek pieces into the trunk of the police car, the Doctor calls and says that she knows the Dalek is a refugee from Skaro. The Dalek insists that all humans are its prisoners and it has weapons, and the Doctor tells it to release Lin. It laughs and the Doctor hologrammatically connects with Lin's biotrack and tells Lin to know that they're coming for her and she should keep fighting. The Dalek reasserts control and insists that the Daleks are supreme, and the Doctor tells it that she kept it chatting so she could reboot the TARDIS systems. Lin drives off and the Doctor heads for the coordinates in the TARDIS.
Graham returns and realizes that the TARDIS is gone, and the Doctor left him behind.
Mitch explains that MDZ is a weapon-research company, and the Doctor discovers that the Dalek is blocking the biofix. She tracks the police car via CCTV cameras, but Lin destroys the cameras with the Dalek blaster and then the junction box. The Doctor switches to satellite tracking, and calls UNIT for help. The operator, Polly, says that she's with the UK Security Helpline and tells the Doctor that UNIT operations were suspended pending review after funding withdrawal by the UK's major financial partners. The Doctor hangs up and tells the others that they're on their own.
Graham shows Aaron a box of things and explains that Aaron's wife kept them and Graham found them after she died. He tells Aaron that his wife said that she gave someone life and was proud to watch them grow, and asks Aaron why he didn't come to the funerals. Aaron explains that he thought that maybe if he wasn’t there, they weren't gone, and wishes he had been there. Graham takes his hand and says that there's still time.
Lin drives to an old farm and the Dalek says that the work will commence. Farmer Dinkle comes out to ask what Lin wants, and the Dalek says that it will be reborn and humanity destroyed. Dinkle tells her to leave, and the Dalek exterminates him. Lin then takes the Dalek pieces and some of the farm machinery into the barn, and uses Dinkle's forge and tools to assemble a casing. Exhausted, Lin hesitates and the Dalek tells her to continue. She says that she will fight and collapses.
The Doctor tracks the police car to the farm and the group finds Dinkle's body. She confirms that a Dalek weapon was used and realizes that was what was at MDZ. They hear something in the barn, and the others insist on going inside with the Doctor. When they enter, Lin calls to them asking for help. The Doctor confirms that the Dalek has left her, and Lin warns them that the Dalek is still there. They hear something moving and the Doctor tells the others to go back to the TARDIS while she finds the Dalek.
Once the others leave, the Doctor explores the barn and the Dalek bursts through the wall in its new casing. The Doctor manages to use her sonic to disrupt its blaster because it's not fully in sync yet, and the Dalek insists that Earth is under the control of the Daleks. She tells them that humanity won't surrender and that the humans banded together and trapped the Dalek for centuries. The Dalek says that it will summon the fleet, and the Doctor tells it that it doesn't have the ability. It scans the Doctor and confirms that she's not human, and she says that she's the Doctor.
The Dalek overrides the sonic and opens fire, and the Doctor takes cover. It says that it has all the information that it needs for conquest, lifts into the air, and flies off. The Doctor returns to the TARDIS and tells the others what happened, and Lin asks if the Dalek will wipe out the world. The Doctor promises that they'll stop it, and Graham calls and tells her to pick him up. He starts to explain to Aaron about the TARDIS, just as it materializes in the house and Yasmin calls them both inside.
The Dalek lands near a windmill farm and soldiers surround it. It orders them to surrender and when they don't, opens fire with its blaster and missiles while ignoring their bullets. Once they're all dead, a tank arrives and opens fire. The Dalek deflects its shell with a missile and destroys the tank.
The Doctor homes in on the heat signal from the blast, and Mitch suggests that they stop the Dalek the same way that their ancestors did. Aaron suggests that they use his oven to destroy the metal parts of the Dalek, and has Ryan help him break it up so that it will fit. Meanwhile, the Doctor realizes that the Doctor is heading for the biggest communication resource in the country: the government communications headquarters.
The Dalek breaks into the HQ building, kills the operator, and diverts all power to the fleet signal transmission. The Doctor realizes what it's doing and the power diversion shuts down the UK's Internet. The TARDIS materializes in the control room and its force field protects the Doctor when the Dalek fires. It says that they have failed and the fleet will be summoned, and the Doctor tells it that humanity will always defeat it. The Doctor tells it to stop the signal and get off of Earth, and it refuses. and she tells it to tell the fleet that she and her mates will protect the planet forever.
The Doctor drops the force field and the group manages to get close enough to grab the Dalek. They attach the microwave parts and activate them, and the Dalek casing heats up and explodes. The Doctor confirms that the signal was never sent, but the creature manages to get to Aaron and possesses him. It demands that the Doctor take it to the Dalek fleet or it will kill Aaron. The Doctor agrees in return for it sparing Aaron's life, and they get in and head for the fleet.
When the TARDIS arrives, the Doctor opens the doors and says that the only thing there is a sun going supernova. The vacuum corridor pulls the Dalek out, but it manages to hold on and the corridor expands to take Aaron with it. Ryan runs to Aaron as he's pulled to the TARDIS door, and tells Aaron that he loves him and holds out his hand. Aaron finally takes it and Ryan pulls him in, while the creature is pulled off of his back and into the supernova. The Doctor closes the doors, and Ryan and Aaron hug.
Back at the dig site, the Doctor asks Aaron if he fancies a trip. He declines and tells Ryan to call him when he gets back. Aaron asks the others to look after Ryan and hugs his son, and the Doctor says that they're heading for... everywhere. Mitch and Lin hold hands and watch them go.
Written by Gadfly on Jan 1, 2019