Oskar, a meek 12-year-old boy, lives with his mother in the western Stockholm suburb of Blackeberg in 1982. His classmates regularly
bullyhim, and he spends his evenings imagining revenge. One night, he meets Eli, a vampire (though he does not know this at first) with the physical appearance of a pale girl his own age. Eli has recently moved in next door to Oskar with an older man named Håkan. Eli initially informs Oskar that they cannot be friends. However, over time, they begin to form a close relationship, with Oskar lending his
Rubik's Cubeto Eli, and the two exchanging
Morse codemessages through their apartment wall. Eli eventually discovers that Oskar is being bullied at school, and encourages him to stand up for himself. This inspires Oskar to finally stand up to his tormentors during a field trip and strike the leader of the bullies, Conny, on the side of the head with a pole, damaging his ear.Meanwhile, Håkan has killed a local resident to provide blood for Eli. However, when he fails to return the blood, Eli finds and kills a local man named Jocke. Håkan attempts to hide his body in the lake, but it is discovered on Oskar's field trip. When his last attempt fails, and he is about to be caught, Håkan purposely disfigures himself by pouring acid on his face, preventing the authorities from identifying him and tracing Eli. Eli finds out where Håkan is being held at the local hospital. Håkan lets Eli in the window and offers his neck for Eli to feed on. Afterwards, he falls out the window to his death.Now alone, Eli goes to Oskar's apartment and sleeps the night with him, during which time they agree to "go steady." Some time later, Oskar shows Eli a private place he knows and suggests that they form a
blood bond, and cuts his hand, asking Eli to do the same. Eli, thirsting for blood, but desperate not to harm Oskar, laps up his spilt blood, and, after begging him to leave, runs away. Soon after, Eli attacks Ginia, a local woman. Her boyfriend, Lacke, who was also Jocke's best friend, turns up just in time to interrupt the attack.Ginia survives the attack, but soon discovers that she has become painfully sensitive to sunlight. Thirsting for blood, she pays a visit to the eccentric Gösta. Gösta's many cats attack her fiercely. In the hospital, Ginia asks an orderly to open the blinds in her room. When the sunlight streams in, she bursts into flames. Lacke, who has lost everything because of Eli, seeks out Håkan and Eli's apartment for vengeance, unaware that Oskar is in the apartment as well. Lacke finds Eli asleep in the bathtub and, as he is about to strike, Oskar distracts him. Eli is alerted by the noise and kills Lacke. Eli realises that it is no longer safe to stay, and informs Oskar of this. The two kiss.The next morning, Oskar receives a phone call from Conny's friend, Martin, who lures Oskar out to resume an after-school fitness program at the local swimming pool. The bullies, led by Conny and his older brother, Jimmy, start a fire to draw Mr. Ávila, the teacher in charge, outside. This leaves Oskar trapped alone in the pool, where Jimmy forces him to hold his breath underwater for three minutes, threatening to cut Oskar's eye out if he fails. As Oskar is underwater, a commotion muffled by the water takes place above the surface. Feet skim across the waterline, and soon, Jimmy's severed head drops into the other end of the pool, followed shortly by his arm, which was holding Oskar down. A
hypoxicOskar is then pulled out of the water by Eli. A closing wide shot reveals three dismembered bodies around the pool and Andreas, the reluctant fourth bully, sobbing on a bench. The film concludes with Oskar traveling on a train, with Eli in a trunk beside him. Inside, Eli taps the word "kiss" to Oskar in Morse code, which he taps back.