When Frank Sterling sets up on his own account as a private detective, his first client, the enigmatic Gloria Etchingham, asks him to investigate a curious line of text and numbers among her disappeared husband's papers. The mystery takes him on a journey to Ypres and the Flanders battlefields of the Great War. A series of further clues, and the race to solve them, lead to murder and kidnapping against a backdrop of political extremism and personal betrayal. Is Keith Etchingham alive or dead? Who are the men pursuing Sterling? What is the real reason for his involvement? In finding all the answers, Sterling has to confront his own flaws as well as the dangers the case brings.