An old woman, Estelle, walks into Round Stone Wood at night, walking carefully so as to not frighten "them." She comes to a fairy circle and sees small glowing creatures flitting about. She takes photos of them and leaves, unaware that they have transformed into large, malignant creatures.
At Torchwood, Jack is trying to sleep and dreams of dead soldiers on a train with their mouths full of rose petals. He gets up and finds a rose petal on his desk. When Ianto comes in, he notes that there are unusual weather patterns.
A young girl named Jasmine Pearce leaves school alone, unaware that a man is watching her from down the street. Her stepfather Roy is running late and drives to pick her up. as Jasmine waits, one girl pulls on her braids and a teacher asks briefly asks after her. Once the teacher leaves, Jasmine starts walking and the man offers her a ride. Jasmine ignores him and continues into a park underpass. She and the man, Mark Goodson, are both unaware that something is watching from the shadows. Jasmine refuses to go with the man, who grabs her. The creature flies down from the sky, the wind rising, and slams the man about, telling Jasmine to run. Goodson gets in his car and looks on as Jasmine skips blithely away.
Jack and Gwen go to a fairy lecture and Jack admits that an old friend invited him. Estelle is giving a speech on "Fairies: Fact or Fiction" and shows the sparse crowd the photos she took the other night. As she talks of fairies being friendly loving creatures, Jack shakes his head and insist that Estelle always gets it's wrong. After the speech, Jack talks to Estelle, who says it's good to see him and mentions that she knew Jack's father. Jack asks to see the rest of her photos.
Goodson walks through Cardiff and seems to hear fluttering noises wherever he goes. Panicking, he runs through the shops and sees something flying toward him. He starts choking up rose petals and runs to a policewoman. When Goodson tries to get in the car, begging for help, she arrests him.
Roy finds Jasmine and brings her home. She refuses to listen to Roy, insisting he isn't her father, and says that nothing can hurt her.
Jack and Owen go to Estelle's home for the photos. Gwen notices a photo of Jack and says that it's his father, who had a relationship with Estelle. Gwen talks to Estelle privately and mentions Jack's father. Estelle notes that she never met Jack and his father at the same time, and that Jack doesn't like to talk about his father. Jack comes out and tells Estelle to call him if she ever sees the creatures again. As they leave, Jack explains that the fairies aren't aliens, but something worse: memories of the past and present, merged together and incredibly dangerous.
Jasmine is playing outside and goes into the nearby woods. Roy and her mother, Lynn, are discussing the child and Roy notes that Jasmine isn't a normal child. In the woods, the fairies call out to Jasmine, inviting her to run away.
Gwen brings up fairy photos from the past and notes that they were proven as fakes. Owen notes that Round Stone Wood has always stayed wild and is rumored to be haunted. Jack warns that their machines can't pick them up and that the only sign of them is odd weather patterns.
Goodson is taken to jail and he tries to explain what happened. He admits that he's done wrong and attacked little girls before. Goodson begs them to lock him up.
As they go to the stone circle, Gwen discusses Jack's father and his relationship with Estelle. He says that he didn't catch up to Estelle until after the war. As they check the stones, Gwen insists that it's not science and Jack warns that it's far worse.
In the jail that night, Goodson looks up as something flies down at him. He screams and the officers to go investigate.
Lynn hears Jasmine talking with someone in her room. She goes in but finds nothing. Jasmine says she was just talking with herself and Lynn wishes she'd laugh more.
The police call Torchwood in. Goodson is dead of oxygen deficiency but there's nothing to suggest any pressure was applied to him. When Gwen examines the body, she finds rose petals in its mouth.
Estelle is at home using a crystal to try and contact the fairies. Something blows out the candles and she goes to the windows. She sees glowing eyes in the dark and the window explodes in his face.
Jack confirms that Goodson was a pedophile and hung around schools. He warns that the fairies can control the elements and use them to kill, and are unkillable. The first thing they must do is determine who the fairies are protecting, since they often fixated on a child, a Chosen One. They're interrupted when Estelle calls to tell Jack that he was right and the fairies are hostile. As the Torchwood team heads out, Estelle hears her cat outside. She tries to call it inside but when she steps out the patio door closes behind her. The rain begins to fall around her.
Tosh determines that there is a localized storm in the area of Estelle's home.
Estelle struggles against the rain pouring down on her and collapses to the ground, choking.
The Torchwood team arrives at Estelle's home a few minutes later. They find her in her garden, drowned. Jack holds her in his arms and Gwen says that it was Jack, not his "father," that met Estelle. He admits it's true, and that the two of them vowed they'd be together until one of them died.
Back at the Hub, Jack explains to Gwen that he met Estelle in London during the War. However, he had seen the petals in the mouths of dead men before that, in a troop train in 1909. They entered a tunnel and when they emerged, all fifteen men were dead, suffocated. They had accidentally run over a child in a village the week ago.
As Jasmine sits in her room, smiling, Lynn hears a dog barking outside. She goes to look but sees nothing, and then goes back inside just before a fairy flies at the door toward her.
Gwen and Rhys return home and find their apartment trashed. Rose petals and dirt are scattered everywhere.
The next day, Lynn prepares for her and her husband's five-year anniversary party while Roy takes her to school. He notes that it's no wonder that her dad left her. As she gets in the car, Jasmine waves to the fairies in the wood. Roy wonders who she's waving to and Jasmine says it's her friends. At school, two girls bully Jasmine, shoving her to the ground. The teacher comes over but Jasmine refuses to identify who pushed her.
Jack goes to see Gwen, who is furious that the fairies have invaded her personal life. When she demands to know what the fairies are and what they want, Jack explains that the fairies were once children, from different moments in time. They want what is theirs: the Chosen One, another child.
At school, the two bullies come after Jasmine again. The winds pick up. At the Hub, Tosh detects the unusual weather patterns. At the school, Jasmine smiles as the two bullies are assailed by high winds and the other children run inside in panic. The teacher comes over to protect them while Jasmine looks on, smiling in triumph.
At Jasmine's home, Roy puts up a fence to separate the garden from the forest.
The Torchwood team arrives at the school and Gwen hears the fairies laughing in the trees. She runs back inside where the others are talking to the teacher. She tells them that Jasmine was there, unharmed, the sun shining down on her. Jack asks after Jasmine and is told she was sent home with the others, and they realize that Jasmine is the chosen one.
Lynn tries to talk to Jasmine and her friends, and how Roy couldn't see them. She tries to get more information about Jasmine's friends, but Jasmine says that they don't like parties but can be anywhere. When Lynn asks when Jasmine met them, the girl explains that her friends said they'd always be there for her, throughout time. They go outside and Jasmine sees the new fence. She pounds on it and Roy goes to get her. She kicks him and Roy slaps her. Thunder echoes through the sky as Roy returns to the party. The wind starts to pick up as Lynn wonders where Jasmine is. Roy calls the partygoers together to announce they plan to have children. However, the fairies arrive in their monstrous forms and attack the partygoers. Torchwood arrives and tries to get everyone out. One of the fairies attacks and kills Roy, while another one attacks Jack. Gwen manages to pull Jack away and the fairies go into the woods. Jasmine walks off after them and Jack and Gwen follow while Lynn cradles the body of her dead husband, his mouth filled with rose petals.
In the woods, Jasmine tells Gwen and Jack that she can see the old forest, the real one. The fairies emerge from the woods and insist that Jasmine is theirs. Jack asks what will happen if they make Jasmine stay with them, and Jasmine warns that the fairies promised that they would kill anyone who gets in the way, raising storms and winds and destroying the world. The fairies assure Jack that Jasmine will live forever with them unharmed. After a moment, he tells them to take the girl. When Gwen tries to intervene, Jack stops her and tells her it's the world's only chance. Jasmine thanks him and goes off into the woods. Lynn arrives just in time to see her daughter disappear. She attacks Jack in a fury and collapses sobbing as he tries to apologize.
As the team leaves, Jack asks them what else he could do but they have nothing to say to him.
Later at the Hub, Gwen is alone, looking at all the fairy photos taken over the year. The computer monitor comes on by itself, showing one of the 19th century fairy photos. Gwen magnifies one of the images and sees that it has Jasmine's face.