We begin with Oskar, a twelve year old boy living with his mother in a suburb of Stockholm. His parents are divorced and Oskar usually keeps to himself. He is constantly bullied by a group of kids at school and dreams of revenge. He collects newspaper clippings of murders, and violent crimes, while also carrying a knife with him. Although he never acts on these violent urges, it simmers just below the surface. Oskar’s interests are peaked with the arrival of new tenants that move into to an adjoining apartment. Eli is a girl that looks to be about Oskar’s age, while Haken is the older man that accompanies her. Oskar and Eli meet outside at a jungle gym a few nights, both seem interested in one another, but their conversations are short. Eli is always bare foot and underdressed for the weather but is never cold. Haken on the other hand packs up a case of curious objects and goes into the woods. After this scene we begin to see what Hakan does for Eli, he kills people and drains there blood for her consumption. Haken has to abandon his kill at the risk of being found out by some hikers and a very inquisitive dog. Eli is not pleased by this and must take matters into her own hands.
As the locals start to suspect Eli in the death of their friend, one of the men breaks into her apartment and finds her asleep in the bathtub. Oskar comes over at just the right time and shouts “No”. This gives Eli the time she needs to pounce on the would be assassin. She tells Oskar that she has to leave town. In the mean time the bully from school has recruited his even more ruthless brother to get back at Oskar. In one of the films final scenes at the schools swimming pool; Oskar is told to either hold your breathe for three minutes or lose an eye. The brother grabs Oskar by the hair and holds him underwater. Oskar starts to loose his breathe and panic. There is an intense commotion up above and a severed head fall to the bottom of the pool. Oskar is released as the arm holding him also starts to fall to the bottom. Oskar jumps to the surface to see Eli has rescued him. Thus completing Eli’s full need and devotion to Oskar. The final scene finds Oskar alone on a train with a large box, with Eli inside. Oskar has become the new Haken.