Based on a real-life story, this pursues a fairly pedestrian beat but it builds its tension excellently and without too blatant use of the usual cloak-and-dagger methods. Director Andre de Toth has sought to get his effects by showing the mental strain of Jack Hawkins in his dilemma rather than by stress on too much physical danger.
Hawkins, a British spy in both wars, and therefore an exile in Germany between the two conflicts, has built up confidence as an astute, loyal and resourceful member of the Nazi machine. At the same time he is feeding the Allies invaluable information through a British agent, neatly played by Felix Aylmer, disguised as an antique clock seller. When Aylmer is arrested and murdered, suspicion falls on Hawkins through his aide, a member of the Gestapo. But he manages to brush off this suspicion and continues his espionage through his new contact, a beautiful singer.
Hawkins plays the role of the general with his usual reliability.