When Heidi goes to live with her bad-tempered and lonely grandfather, Uncle Alp, in his hut on the mountain, everyone thinks that her stay will make them both unhappy. But Heidi soon makes new friends and grows to love her new life. Then her aunt Detie arrives and insists that Heidi must go to live with a family in Frankfurt. Heidi and her grandfather are heartbroken. Will Heidi ever return to the mountain?