Summer 1914. Cambridge student Emily Grey is studying German in Heidelberg where she meets Hans a philosopher who wins her heart and asks her to marry him. When the First World War intervenes however she is forced to return to England leaving Hans behind to join the Imperial Navy. A year later Emily is recruited to serve in a recently established government department. Commander Cumming head of His Majesty's newly formed Secret Service is keen to make use of Emily's language skills. Interviewing an informer known as 'The Dane' she learns of a plot with the potential to change the course of the war. Emily must work undercover to locate the mole the heart of the British naval establishment. Who is the traitor known only by the codename 'Heiffer'? Can she find him in time to prevent a military catastrophe that would spell disaster?
