The adventures of Heidi, written by Johanna Spyri in 1880 and 1881, tell the story of a young 5-year-old Swiss orphan girl placed with her grandfather (a hermit living in the Grison/Graubünden mountains) then sent to Frankfurt, to the Sesemann family, as companion to their daughter, Clara, who is confined to a wheelchair.
Despite the friendship that develops between the two young girls, Heidi soon begins to feel homesick. After several bouts of sleepwalking and increasing depression, she is sent back to the mountains to join her grandfather, Peter and his goats.
A short time later, Clara comes to visit Heidi and finally manages to walk. Clara returns to Frankfurt, promising to return to see the girl who changed her life. Heidi stays in the mountains to live with her grandfather and Peter.