The story is narrated by Rosemary Cooke, a college student recalling her family and childhood. Rosemary's father, a behavioral psychologist, adopted a chimp into the family when Rosemary was very young. She grew up thinking of this chimp, Fern, as her sister--until Fern was abruptly banished from the family. This happened very abruptly when Rosemary was five years old. Rather than telling her about this major change, her parents sent her to her grandparents' home, so that when she returned, Fern was gone. Fern's banishment from the family changes the entire family dynamic. The father develops a drinking problem and behaves with chronic anger. Rosemary's older brother resents his parents' actions in regard to Fern. He becomes estranged from the family. He runs away and joins a radical animal activist group. He is viewed by the authorities as a terrorist and must live furtively, like a fugitive. Rosemary misses Fern and also feels guilty about the chimp's dismissal from the family. She wonders if something she said about Fern caused her parents to make the decision for Fern to leave. While Rosemary is in college, her brother visits her, telling her that Fern now lives in a research lab. During this visit, her brother also has a brief dalliance with a friend of Rosemary's. Eventually, with the psychologist father now dead and the brother still living in hiding, Rosemary and her mother re-locate to live near the lab where Fern is kept. They re-develop a relationship with the simian member of their family.
Best part of story, including ending:
The novel is entertaining yet also makes the reader stop and think about relationships between humans and animals, and about the ethics of animal experimentation.
Best scene in story:
The scene where Rosemary reunites with her brother while she is in college. The two of them talk, and Rosemary gains new insight into events she only partially understood when she was younger.
Opinion about the main character:
The fact of having had a chimp as a sister gives Rosemary an unusual and humorous perspective on psychology, science, gender, religion and many other topics. Although the story is about a family's grief, Rosemary's narrative voice imbues the story with humor.