Rose and Fern are twins, and as close as two sisters can be. The story is told using Rose’s diary about their disturbing childhood with a mother who is clearly a sociopath, alternating with Fern’s sunnier day to day life as a librarian with certain sensory processing issues. Rose desperately wants a child, but cannot seem to become pregnant. Fern, meanwhile, is falling in love with a mysterious library patron from the US. It soon becomes clear that Fern and Rose have very different experiences and memories of their childhoods, and Rose’s belief about their mother and some long-held secrets may be completely wrong.