The story of an English spy in Germany during the First World War. The spy is an young man with a gift for languages who joins the army against his family's wishes. His gift is discovered and he is sent into the enemy country. A series of remarkable adventures, including the destruction of a zeppelin and the necessary murder of a scientist, make the book thrilling. Additional interest is added by his relationships with a German intelligence officer and with a young woman whose tragic death will ultimately prove his undoing.