1940. Guernsey is first bombed, then occupied, by the Germans. A year earlier, young, naïve and recently married Helene, waves goodbye to her husband, who has enlisted in the British army. Protected only by her father and nanna, Helene must carve out a life on the island for the length of the war. Forty years later, her daughter Roz begins a search for the truth about her father, and stumbles into the secret history of her mother's life.