Persons of Interest does not fit readily into any familiar genre. It crosses the borders of biography, psychology, Cold War history, and family studies. When Pamela Burton and her sister Meredith Edwards decided to write a book about their parents, they realised that different readerships would be attracted to different parts. Who would be interested in a book about the marriage, and the post-divorce lives, of a man who had been a central figure in public controversies many decades ago and a sensitive, introspective woman who was little known to the public but for whom their daughters felt far greater sympathy? By crossing those borders with what their prologue calls ‘a unique, intimate and candid account of our parents’ complexities and interweaving relationships’, they have written a book that will be ‘of interest’ to many readers, no matter what their usual focus.