Rosemary Cooke talked non-stop as a child in Bloomington, Indiana but grew up to be a quiet student at The University of California, Davis. She's been in college too long, unable to settle on a major and troubled by the long ago disappearance of her sister and brother.
We come to learn that Rosemary's father was an experimental psychologist and - around the time Rosemary was born - the Cooke family took in an infant chimp to raise as a member of the family. The chimp, Fern, was reared as a sister to Rosemary and her older brother Lowell until she 'disappeared' when Rosemary was five years old.
Karen Joy Fowler does a masterful job of slowly revealing how this incident profoundly affected the Cooke household. We come to know, understand, and empathize with each member of the family (mom, dad, Lowell, and Rosemary) as they deal with the effects of this aborted experiment. Some light relief is provided by Rosemary's interactions with college acquaintances, which also gives us insight into her behavior and personality.
This is a deeply moving, though somewhat disturbing, story with lessons to teach about how humans treat our fellow animals. Good book, highly recommended.