"Information about the secret Anglo-German treaty was reaching Russia through some inexplicable leak in the British Foreign Office. And on the Riviera, Sir Ronald Milbank, the distinguished Under Secretary of State for Foreign Affairs, was seen everywhere with the notoriously beautiful Valerianova Jurovsky, while his lovely step-daughter showed a marked preference for the company of Russian noblemen. So young Brett Carstairs had to follow the movement not only of Soviet spies but of British statemen, follow them from the Casino at Cannes to Vigo's exclusive den in London, block their ruthless schemes and try to find out if the girl he loved was betraying her country."