Heidi is an orphaned girl initially raised by her aunt Dete in Maienfeld, Switzerland. In order to get a job in Frankfurt, Dete brings 5-year-old Heidi to her grandfather, who has been at odds with the villagers for years and lives in seclusion in the mountains. He at first resents Heidi’s arrival, but the girl manages to penetrate his harsh exterior and subsequently has a delightful stay with him and her best friend, young Peter the goat-herd.
Dete returns three years later to bring Heidi to Frankfurt as a companion of a 12-year-old disabled girl named Clara Sesemann. Heidi spends a year with Clara, clashing repeatedly with the Sesemanns’ strict housekeeper Miss Rottenmeier and becoming more and more homesick. Her one diversion is learning to read and write, motivated by her desire to go home and read to Peter’s blind grandmother. Heidi’s increasingly failing health and several instances of sleepwalking prompt Clara’s doctor to send her home to her grandfather. Her return prompts the grandfather to descend to the village for the first time in years, marking an end to his seclusion.