At a finger buffet held at 24 Beech Drive on the day of Charles and Diana's wedding, Rebecca Monroe's mother locked herself in the bathroom and never came out. Was it because her squidgy chocolate log collapsed? Because Rebecca's grandmother married her first cousin? Or can we never know why we do what we do? According to Rebecca's scientist husband, our genes control our fate, but Rebecca is less sure. Can science explain everything? Love? Chance? Who shot JR? Charting her family history, Rebecca discovers that it's not just a habit of quoting proverbs and a recipe for sherry trifle that have been passed down the maternal line. Three generations of mistaken marriages, dubiously fathered children and untimely deaths make up the Monroe family DNA. Is Rebecca simply the next twist in the double spiral? Or is Aunty Suzanne, the women's libber, right? That biology need not be destiny? In this tragicomic history of one British family, Carole Cadwalladr asks the most fundamental of questions: who, how and why we are.