The film is based on a 2003 novel by the same name, written by Norwegian author Jostein Gaarder. The main character is the young boy Georg who one day finds a long letter from his deceased father. The letter tells, among other things, about the father's youthful love for the mysterious "orange girl" (appelsinpiken), and leaves a mystery for Georg to solve.

A moving, magic and playful story about a young girl who, at the end of her life, learns to accept death and understands how wonderful life really is. The script is based on the novel by Jostein Gaarder.