Annie John, the protagonist of the book, starts out as a young girl who worships her mother. She follows her everywhere, and is shocked and hurt when she learns that she must some day live in a different house from her mother. While her mother tries to teach her to become a lady, Annie is sent to a new school where she must prove herself intellectually and make new friends. She then "falls in love" with a girl by the name of Gwen. She promises Gwen that she will always love her. However, Annie later finds herself admiring and adoring a girl that she called the "Red Girl". She admires this girl in all aspects of her life. To Annie this girl is the meaning of freedom because she does not have to do any daily hygienic routines like the other girls.
Annie John is then moved to a higher class because of her intelligence. For this reason, Annie is drawn away from her best friend Gwen and the Red Girl, while alienating herself from her mother and the other adults in her life. It later becomes clear that she also suffers from some kind of mental depression, which distances her from both her family and her friends. The book ends with her physically distancing herself away from all that she knows and loves by leaving home for nursing school in England.