Chapter 1 opens with a childhood memory of Shapiro looking into the bathroom mirror and sensing something is amiss. It then jumps forward several decades. At the age of 54, in a hotel room in San Francisco, Shapiro gazes at her reflection and sees a stranger staring back at her. What was familiar has disappeared. Her reaction is visceral. She reminds herself she is the person she always was.

Chapter 2 takes place in Shapiro’s home in Connecticut, 24 hours before her trip to San Francisco. She receives the results of a genetic test taken by Susie, her older half-sister from her father’s first marriage. Paul died decades earlier in a car accident, leaving the sisters with questions about their risk for hereditary diseases. Shapiro describes her pride in belonging to a large Orthodox Jewish family through her father. She recalls taking a DNA test after her husband, Michael, became curious about his own ancestry several months earlier. The results revealed that Shapiro was 52 percent Eastern European Ashkenazi (a Jewish ethnicity). The remaining 48 percent was a mix of French, Irish, English, and German. Confident in her heritage and identity, Shapiro assumes there is a reasonable explanation for her test results, including historical migrations and conflicts.