Oskar, a lonely outsider who is twelve years old and lives in the suburb of Blackeberg in Stockholm, is mistreated at school by his classmates; at home, Oskar fantasizes about exacting revenge on a trio of bullies. The story takes place in 1982. He strikes up a friendship with Eli, his twelve-year-old next-door neighbor, despite the fact that he can only be seen on the snow-covered playground outside their building at night.