The episode begins, how could it be otherwise, with Rose, a 19-year-old who lives with her mother Jackie in London. Rose works in a department store and has a normal day ahead of her, or so it seems. When her shift ends and she is about to leave the building with everyone else, she is reminded that she has not yet handed in her lottery money, so she makes a last-minute trip down to the basement to the office. There the unthinkable happens: the mannequins that are stored here attack her! Just when there seems to be no way out for her, he appears, the doctor. He saves them without explaining too much, but he seems to know what he is doing. They escape from the building and the Doctor advises Rose to get away from the building quickly, which she does. Just then the department stores' suddenly explodes.
Rose rushes home. In her hand she still has an arm from one of the mannequins. Arriving at her destination, she asks her concerned friend Mickey, who has heard about the explosion, to dispose of the arm. The next morning, the doctor appears at her home just as abruptly as when they first met, because a signal has brought him here. And indeed: the doll's arm is still alive and has gained access to the flat! With the help of his sonic screwdriver, however, the doctor manages to render him harmless once and for all. Afterwards, the doctor disappears again without explaining anything.
Rose, however, can't forget the strange man who said such confused things and starts investigating. She finally finds someone on the internet, Clive Finch, who has probably been looking for the doctor for a long time. Together with Mickey, she goes to see him. Once there, Clive explains to Rose that the doctor has always appeared in different eras and always looks exactly the same, never older or younger. And death always accompanies him.
Mickey, who had been waiting in the car, meanwhile had an unpleasant encounter with the plastic. When Rose leaves Dave's house, a duplicate of Mickey is now waiting for Rose, which she doesn't notice, but she does notice that he is behaving strangely. When the two are about to have lunch in a pizzeria, the doctor reappears and reveals Mickey to be a mannequin.
The Doctor then joins Rose in a search for the source of the living plastic. To do so, he takes her to the TARDIS, a blue police emergency cell. But the outer appearance is deceptive, the emergency cell is only the camouflage of his indescribably highly developed means of transport. It is much smaller on the outside than on the inside. Within the blink of an eye, the TARDIS, following in the plastic's footsteps, takes them both to another location within London. Rose, finally, is the one in the London Eye who recognises the amplifier of the signal that triggered what happened. Rose and the Doctor therefore go to the sewers below London. There they find the real and alive, if very frightened, Mickey. Also living down there is the Nestene Consciousness, which controls the plastic. It apparently wants to take over the entire planet in order to get its hands on the raw materials; the only thing standing in the way of a successful invasion are the humans. Therefore, at this moment, the Nestene consciousness sends out a signal that brings all of London's mannequins to life. These attack humans all over the city.
With the help of Rose (and a weapon called the "Anti-Plastic"), after a failed attempt to end the conflict peacefully, the Doctor finally manages to defeat the creature and prevent the hostile takeover of the planet.
The Doctor is impressed with Rose. She has shown that she is brave and smart and that she has a good heart. Finally, he makes her an incredible offer: he offers her to travel with him, through time and space. And although she hesitates at first, as she would have to leave her mother and Mickey behind, at least temporarily, she can't help but agree. What adventures would await her out there?
