Let the Right One In (Original Swedish: Låt den rätte komma in), also known as Let Me In, is a 2004 vampire fiction novel by Swedish writer John Ajvide Lindqvist. Centering on the relationship between a 12-year-old boy, Oskar, and a centuries-old vampire in the form of the female human child, Eli. The story takes place in Blackeberg, a working class suburb of Stockholm, Sweden in the early 1980s. Focusing on the darker side of humanity, the novel deals with issues such as bullying, drugs, theft, pedophilia, prostitution and murder in addition to the obvious supernatural theme.After becoming a bestseller in the author's home country of Sweden, it has was translated into Danish, German, Russian, English and Chinese in 2007, and Finnish in 2008. Confusingly, when it was translated into English, the American version underwent a name change to "Let Me In" while the British version retained the original title. Additional translations include Italian, Spanish, Polish, and Norwegian. The Swedish-language film version titled Let The Right One In was directed by Tomas Alfredson, and was released in 2008 to widespread critical acclaim. The English-language film version titled Let Me In was directed by Matt Reeves, and was released October 1, 2010.
12-year-old Oskar lives with his mother, who is loving and with whom he initially seems to have a good connection. As the story unfolds, it turns out he is being bullied at school. Since his father is an alcoholic who lives out in the countryside, there is no man in the house for him to turn to. Oskar seems intelligent, but has some morbid interests including crime scenes and forensics, and keeps a scrap book with newspaper clippings about murders. He befriends a new girl who moves in next door whose name is Eli. Eli lives with an older man named Håkan, a former teacher who was fired and became a homeless transient when he was discovered to be a pedophile. After it is revealed to Oskar that Eli is a vampire, he ignores her dangerous nature and chooses to remain friends. The two children develop a closer relationship when Eli helps Oskar fight back against his abusers. Through the course of the novel their friendship gradually becomes closer and they share more of themselves - particularly Eli's lengthy history.Håkan loves Eli, and serves her by gathering blood from the living, while at the same time fighting against his conscience. He chooses victims he is physically able to trap, but who are not too young. Eli pays him for doing this, though Håkan makes it clear he would do it for nothing if Eli allowed them to be physically intimate. Eli keeps her money in several boxes, along with a variety of different puzzles. Apart from a few items of clothing and food, this is all that fills the apartment. After several failed attempts to acquire enough blood for Eli, Håkan's nature surfaces once again as he promises to go out one last time if they can spend the night together. With the limitation that he may only touch Eli, they come to an agreement, but Håkan must get the blood first.
Håkan's final attempt to get blood for Eli fails, and to avoid the police being able to trace him back to Eli, he purposely disfigures himself with acid. Håkan offers his own blood when Eli finds him in the hospital, and she drinks him dry as as he sits on the window ledge. Eli fails to kill him when a guard interrupts them - meaning that he will not end up becoming a vampire like Eli. Håkan then throws himself out of the window, bursting upon the ground below. Though the fall kills him, Håkan is later resurrected as a vampire himself, but is mindless and seeks only to find Eli. Eli is trapped in a basement briefly, but manages to escape. Håkan is later beaten to death. Lacke believes a child may be responsible for the murder of his best friend, Jocke (whom Eli fed on before snapping his neck). Later, he sees Eli in the form of a small, shapeless creature as she lunges from the trees at his on/off girlfriend, Virginia. Eli attempts to drink her blood, but is interrupted by Lacke. Virginia succumbs to vampirism, but does not realize the depth of her "infection" until after she attempts to avoid killing by drinking her own blood to satisfy her craving. She learns she must avoid the sun, which boils her skin upon exposure, and later in the hospital Virginia uses this knowledge by deliberately exposing herself to daylight. She successfully commits suicide, bursting into flames.
Oskar finally fights back and injures his main tormentor, causing the boy's older brother to hunt him down and attempt to exact his revenge. Eli rescues Oskar once again, and the two flee the city with nothing but the remaining money, puzzles and each other.