Heidi is an orphan and lives with her mother's sister, Aunt Dete, who has been raised Heidi since infancy. Aunt Dete has a selfish attitude and resents the child. Even though she chose to raise Heidi, she sees the girl as a burden and an imposition.
Aunt Dete decides to take a job in Frankfurt and send Heidi to live with Heidi's mysterious grandfather, even though Aunt Dete has concerns about him. She tells a neighbor about some of the grandfather’s past behavior, and he does not sound like a good guardian for a child. Several people try to talk Aunt Dete out of her decision, but she stands firm and takes Heidi to her grandfather's home, where Aunt Dete exchanges harsh words with the grandfather before leaving.
Now I must go my way and you are Heidi’s next of kin. If you don’t want to keep her, do what you please with her.
Heidi eventually forms a strong bond with her grandfather. Aunt Dete, however, feels guilty about how she treated Heidi and finds a good home for her with a rich family. They have a daughter her age, named Clara, who uses a wheelchair. Aunt Dete has better intentions this time, but she pulls an unwilling Heidi from a home and a grandfather that she loves. Even when Aunt Dete attempts to be kinder to Heidi, she is cruel.