Julia Brannon, an elderly woman who has moved into a retirement home is the protagonist of the novel, The Other Sister. Physically but mentally alert and acutely observant and intelligent, she is a feisty and at times cantankerous protagonist. Her daughter, Rachel, and her grand-daughter, Thea, have given her, as a move-in present into the retirement home, a laptop computer on which they ask Julia to record events from her past. Julia's recorded anecdotes cover many major historical events that affected Julia over the last century. Born into a well-to-do family, Julia, unlike her identical twin sister, Jane, aspired to a life other than marriage and children. She rejected a suitor, whom her sister subsequently married, and chose to study philosophy in a era when there were few female philosophy students and graduates. After her graduate studies she remains at the university as an associate professor although she is never promoted to a full professor. She remains at her job until an event concerning her twin sister compels her to reexamine her choices and take another path. There is, at the heart of the novel, a startling mystery and revelation on which the plot depends, which is crucial to how Julia learns to apprehend "the other."