Dan talks to Richard van Emden about his new book - Missing: the need for closure after the Great War. The backbone of the book is based on the best single story of World War One that he has found in 35 years of research. It is the story of one woman’s relentless search for her missing son’s body. A story with incredible twists and turns. Against the odds she finds him in 1923. Richard also looks at the bigger picture: how long should the nation search for its dead and the mistakes made identifying the dead, when exhumation parties were under such intolerable pressure.