Gustav is a spy employed by the British Secret Service. Although he writes excellent reports, it is soon suspected that he is not actually traveling into Germany to get the information. Ashenden is sent to Gustav's home to determine if this star spy is really doing his own work or not. Ashenden convinces Gustav to tell him that he is not really going into Germany, only getting information by word of mouth. As a bargaining chip, however, Gustav gives information about Grantley Caypor, a man believed to be an English traitor.