Four young British soldiers find themselves trapped behind enemy lines at the height of the fighting on the Western front in August 1914; unable to get back to their units, they shelter in the tiny French village of Villeret. Living in daily fear of capture and execution, they are fed, clothed and protected by the villagers including the local matriarch, Madame Dessenne, the baker and his wife. The self-styled leader of the band of fugitives, Private Robert Digby, falls in love with the 20-year-old-daughter of one of his protectors and in November 1915, with war waging a few miles away, she gives birth to a baby girl. The child is just six months old when someone betrays the men to the Germans. They are captured, tried as spies and summarily condemned to death. Using the testimonies of the daughter, the villagers, detailed town hall records and most movingly - the soldiers' last letters - Ben MacIntyre reconstructs an extraordinarily story of love, duplicity and shame - ultimately seeking to discover through decades of village rumour the answer to the question, Who betrayed Private Digby and his men?.