In what appears to be a normal street, but probably isn't given that this is an episode of Doctor Who, normal things are happening. A council worker does some maintenance on the road while two boys play soccer in a front garden. Chloe, a young girl watches things from her bedroom window.
An old woman walks along the street, but suddenly stops in confusion. Trish, Chloe's mother comes out of her house and asks if everything is all right. The woman says that it's happening again, and urges the boys playing soccer to get inside.
The old woman argues with the father of one of the boys. In her bedroom, Chloe begins to draw one of the boys. The father says that he's watching the boys, but when his and the old woman's backs are turned, the boy Chloe is drawing disappears.
The TARDIS materialises in between two gates, but when the Doctor tries to exit he finds that the gate is blocking the way and he can't get out. He goes back inside and the TARDIS disappears and reappears, this time the right way round.
The Doctor and Rose emerge, and he tells her that they're just in time to watch the 2012 Olympics in London. So it would seem that for once the TARDIS has ended up where it's supposed to be.
As they walk along, Rose notices posters of missing children on a lamp post. The children have all gone missing in the past few weeks, which the Doctor remarks on as well as the fact that something appears to be reducing the temperature of the street. Rose notices that something is scaring the people in the street, but by this time the Doctor is already at the other end.
The Doctor crouches down next to the small soccer goal where the boy disappeared. He holds out his hand, as if he's feeling for something.
As Rose hurries to catch up with the Doctor, a car driving past cuts down. The council worker offers to help push it, saying that it's the fifth time that it's happened that day.
Rose gives a hand as well, and they push the car a little way before it suddenly starts up again. The worker says that cars have been doing it all week, and when Rose asks, says that it's probably happened since the children started going missing.
The father from earlier catches the Doctor with his hand outstretched and asks him what he's doing. The Doctor claims to be a police officer, using his psychic paper to prove it, although the father remains sceptical.
Rose has rejoined the Doctor, and quite a crowd gathers, including Trish, the council worker, and the old woman. A conversation starts up, which gets more and more heated until the Doctor tells everyone to put their fingers on their lips, which they do. The Doctor asks if it's correct that three children have disappeared in the last six days, and the old woman replies that she doesn't care who the Doctor and Rose are just as long as they can help.
The Doctor's investigation begins at the front lawn where the boy playing soccer disappeared. He smells something metallic, which Rose does as well. They go to investigate where another of the children disappeared, and the Doctor feels the same sensation in his hand and smells the same smell.
Trish goes up to Chloe's bedroom to try and persuade her to come down, but Chloe is busy drawing. She notices that Chloe has drawn the boy who disappeared, and asks why she drew him so sad.
Chloe says that she didn't do that, he made himself sad. For that reason she's drawing a cat which will be his friend.
Trish tries to distract Chloe by showing her a news report about the Olympics and telling her that the Torch will be passing near their street. When that doesn't work, Trish tries to ask Chloe about nightmares that she's been having, but Chloe says that she's busy, and threatens to draw Trish.
Rose discovers a cat, which looks like the one Chloe is drawing. She watches the cat wander into a cardboard box, but then it disappears. Once again the Doctor is able to detect the strange sensation and the smell.
Chloe sits in her bedroom and says, apparently to no one in particular, that she's give them friends but still they moan, looking at all the drawings of children that she has made as she says this. She starts to draw again, but her pencil snaps and so she scribbles on the paper in frustration.
The Doctor and Rose split up to try and find the source of the disappearances. As is walking past the garages for a block of flats, she hears something from inside one of them.
She opens it, and a tangled scribbled ball flies out at her. The Doctor hears her cries and comes running. He points his sonic screwdriver at it, and it collapses into a much smaller ball.
The Doctor examines the ball in the TARDIS and is surprised to discover that it's made of graphite. He takes a pencil from his pocket and uses it to start rubbing the ball away.
The Doctor wonders why anyone would bother to create a living scribble, and Rose comments that you'd scribble over something like a drawing. She suddenly realises that it could be a child's drawing and remembers seeing Chloe watching from her bedroom window, and that there was something about Chloe that gave Rose the creeps.
The Doctor and Rose go to Chloe. At first Trish is reluctant to have anything to do with them, but she changes her mind when she asks whether the Doctor can help Chloe and he replies in the affirmative.
The Doctor asks about Chloe and Trish says that she just stays in her room and won't talk to Trish. The Doctor asks about Chloe's father and Trish says that he died a year earlier.
Rose asks if she can use the bathroom, and after going upstairs, spots Chloe coming out of her bedroom. Rose sneaks in and immediately sees the pictures on the wall.
Rose is startled by a rattle from the wardrobe, and she knocks a pencil holder into the floor. She picks up the pencils, and when she looks again, the expression a boy in one of the pictures has changed, which Rose notices.
Chloe enters the kitchen, and the Doctor tries talking to her. She's not very responsive, but she does says that they won't stop moaning, no matter how much she tries to help them.
In Chloe's room, the wardrobe doors rattle again. Rose opens the wardrobe, and a breeze starts blowing. Rose pushes the clothes aside and sees a drawing of a bearded man with glowing red eyes, who says that he's coming to hurt her, although the “her” probably refers to Chloe rather than Rose.
Rose calls for the Doctor, and he runs upstairs to Chloe's room where he sees Rose standing frozen to the spot staring into the wardrobe. He closes the wardrobe door without bothering to look inside.
Rose says that she saw a drawing of a man's face, and Chloe says that she drew her father because she had a dream about him. Chloe says that they need to stay together, and when Trish agrees, Chloe says that the they doesn't include Trish.
Rose asks Trish if she's seen the pictures move, and Trish gets angry and Rose's question and her sneaking into Chloe's room. The Doctor presses the issue, and Trish eventually gives in.
In the kitchen, Rose says that Chloe is drawing people and they end up in her pictures. She wonders about the picture in the wardrobe, and the Doctor says that if living things can become pictures then perhaps pictures can become living things.
The Doctor does some telepathic voodoo, and Chloe lies back on her bed and begins to talk in a strange whisper. Whoever it is talking through her says that they want Chloe.
The Doctor tells the being to identify itself, and it says through Chloe that it's one of many and was travelling with its brothers and sisters but now is alone, and hates it. When asked for a name, it replies that it's Isolus.
Chloe begins to draw something, and the Doctor says that it's the Isolus Mother. He explains that the Mother drifts in deep space and casts off her children.
The children take thousands of years to grow up, and during that time they're sustained by their empathic link for each. They basically can't survive alone, apart from the others. The Isolus have the ability to create make-believe worlds in which they play, and that keeps them happy so that they can feed off each other's love.
Chloe continues to draw, and the Doctor says that it's a solar flare from the sun. That would have created a wave of energy that scattered the Isolus pods.
The Isolus inhabiting Chloe says it was drawn to heat and then to Chloe because she was alone, just like it. The Doctor says that he understands, but the Isolus can't stay in Chloe and can't steal any more friends.
Chloe begins to shake, and there is a pounding on the wardrobe door, followed by the voice that was heard earlier saying that he's coming to get Chloe. The Doctor asks how Trish calms Chloe down, and Trish says that she sings to Chloe, which the Doctor tells her to start doing. The singing works, and Chloe falls asleep, the voice and pounding having stopped.
The Doctor and Rose leave Trish's house and return to the TARDIS, which the Doctor says should be able to trace the pod. As they leave, Chloe watches from her bedroom window, before sneaking out and watching them enter the TARDIS.
Inside the TARDIS, the Doctor and Rose talk while the Doctor works on a device to track the Isolus pod. In the conversation, the Doctor makes an offhand remark that he was a father once. I don't think this is supposed to be a big revelation, as one of the First Doctor's original companions was his granddaughter, or at least claimed to be, and if he had a granddaughter then he obviously had to have had children.
The Doctor completes the device and a screen in the TARDIS indicates that the pod is somewhere in the street. Meanwhile, Chloe is back in her bedroom drawing a picture of the the Doctor and the TARDIS.
The Doctor and Rose leave the TARDIS, Rose slightly ahead of him. She hears a crash from behind her, and sees the device the Doctor had just constructed lying in pieces on the ground. The Doctor and the TARDIS are nowhere to be seen.
Rose returns to the house, where she discovers that Chloe has drawn the Doctor and the TARDIS. She demands that Chloe bring them back, but Chloe, speaking as the Isolus, refuses.
Rose realises that the tar being laid on the road would have been hot, and the Isolus might have been drawn to it. She takes an axe from the council worker's van and smashes through the tarmac of the road, finding the pod.
In her bedroom, Chloe watches the TV broadcast of the Olympic stadium, where people are waiting for the Torch to arrive. She blocks the door with a chair and begins to draw the crowd in the stadium.
Rose returns to the house with the Isolus pod. She catches sight of the Olympic stadium on TV, where the entire crowd has disappeared.
Chloe says that the crowd is not enough. She opens an atlas and starts to draw the earth, while the TV commentator mentions something about Torchwood.
Rose breaks a hole in Chloe's door with the axe and is able to open it. She moves towards Chloe, but the wardrobe doors rattle, and the Isolus tells Rose that if she stops Chloe, it will let the drawing of Chloe's father out.
Rose tells the Isolus that it has its pod and just needs heat, but the Isolus says that the pod is dead, and will need more than heat. The council worker, who had followed Rose into the room says that one of the pictures moved.
The picture that moved is the drawing of the Doctor and the TARDIS, which now has a drawing of the Torch. Rose realises that the Doctor drew that, but comments that the pod needs more than heat.
At that moment, the TV commentator says that the Torch has become more than just a torch, and it's now a beacon. A beacon of hope, fortitude, courage and love.
Rose goes running out of the house and down to the end of the street, where a crowd has gathered to watch the Torch go by. She gets close enough the the Torch bearer, and throws the pod at the Torch, telling in to feel the love.
In her bedroom, Chloe stops drawing the Earth, and the Isolus emerges from her and flies away. Elsewhere, the missing children reappear in the places they disappeared.
Rose doesn't see the Doctor, but then she realises that if all of Chloe's drawings have come to life, that would include the one of her father. She returns to the house and tries the front door, but it's stuck, with Trish and Chloe on the other side.
They hear the voice from the drawing once again say that it's coming to hurt Chloe. Rose tells Chloe that it's only real because she's scared.
Trish tells Chloe that she'll never be alone again, and then the two of them start to sing. As their voices get stronger, the voice of Chloe's “father” fades away.
The Doctor hasn't reappeared though, and an upset Rose watches the TV broadcast of the Torch procession. The Torch bearer collapses, and a familiar figure picks up the Torch.
It's the Doctor, and he carries the Torch into the stadium and lights the flame. It's a good thing that nothing elaborate was planned for the lighting of the flame, although it would have been interesting to see the Doctor emulate the athlete who lit the flame in Beijing. As he lights the flame, the Doctor tells the Isolus to join its brothers and sisters, and it flies away.
The Doctor returns to the street, where Rose joins him. They talk for a while, and then the Doctor looks up and says that there's something in the air – a storm is coming.
Quotes
The Doctor: Only seems like yesterday a few naked Greek blokes were tossing a discus about... wrestling each other in the sand with crowds stood about, begging... no, wait a minute... that was Club Med.
The Doctor: Did you ever have one of those little cakes with the crunchy ball bearings on top? Do you know those - those things? Nobody else in this entire galaxy's ever even bothered to make edible ball bearings. Genius.
Rose: Aren't you a beautiful boy?!
The Doctor: Thanks! I'm experimenting with back-combing.
The Doctor: Are you deducting?
Rose: I think I am.
The Doctor: Copper's hunch?
Rose: Permission to follow it up, Sarge.
The Doctor: It's the pod! It is in the street! Everything's coming up Doctor!