Anthony Blunt (Ian Richardson) is an eminent Cambridge-educated art historian who is also working as a spy for the Soviet Union. In love with double agent Guy Burgess (Anthony Hopkins), he helps Burgess get yet another treasonous British agent to safety in Moscow. When Burgess unexpectedly defects as well, the government becomes suspicious of Blunt, but investigators have trouble believing such a refined and aristocratic gentleman would ever betray his nation and his class.