Rosemary is the narrator and protagonist of this book. She is an unreliable narrator, often commenting on the faultiness of memory. She also breaks the fourth wall and directly addresses the readers throughout the book, creating a personal relationship between the reader and herself. Her story is non-linear and alternates primarily between her college years and flashbacks to her early childhood, when Fern was still around. Rosemary is very unsure of herself and her purpose. She is not sure who is actually her friend, she chose her college in hopes that her brother would return to the town, she is not sure what she wants to study, and she is not sure which memories are true or false. Being compared to Fern for the first five years of her life made Rosemary into an extremely jealous person, and she often seeks validation from external sources, particularly her brother.

Rosemary often feels different from other humans, like she is part chimp. As a child, classmates called her “monkey-girl,” and there are many times in her adulthood when Rosemary feels her inner “monkey-girl” coming out and making her weird and incomprehensible to other humans.

Much of Rosemary’s life is constructed around trying to fill in holes where things have gone missing, primarily her brother and sister.