Twenty-five years after her passing, Audrey Hepburn remains the most beloved of all Hollywood stars, known as much for her role as UNICEF ambassador as for films like Roman Holiday and Breakfast at Tiffany's. Several biographies have chronicled her stardom, but none has covered her intense experiences through five years of Nazi occupation in the Netherlands. According to her son, Luca Dotti, "The war made my mother who she was." Audrey...