Heidi leaves her beloved Alm and moves to Frankfurt, where she finds a new good friend in Clara. Aunt Dete wants Heidi to leave her grandfather on the mountain pasture and go with her to Frankfurt, where she is supposed to live with the Sesemann family and keep their paralyzed daughter Clara company. In this way, Heidi would enjoy an excellent upbringing and grow up with one of the richest families in Frankfurt. Aunt Dete sees a bright future for Heidi in the city. However, this idea is not met with enthusiasm by Heidi and her grandfather, Peter and his grandmother are also very reluctant to let Heidi go. After much persuasion and many promises from Aunt Dete, Heidi finally leaves her beloved mountain world with a heavy heart and travels to Frankfurt.