It is autumn 1981 when the inconceivable comes to Blackeberg, a suburb in Sweden. The body of a teenage boy is found, emptied of blood, the murder rumored to be part of a ritual killing. Twelve-year-old Oskar is personally hoping that revenge has come at long last---revenge for the bullying he endures at school, day after day. But the murder is not the most important thing on his mind. A new girl has moved in next door---a girl who has never seen a Rubik’s Cube before, but who can solve it at once. There is something wrong with her, though, something odd. And she only comes out at night.