Called out of retirement to settle the affairs of a friend, Smiley finds his old organisation, the Circus, so overwhelmed by political considerations that it doesn't want to know what happened. He begins to follow up the clues of his friend's past days, discovering that the clues lead to a high person in the Russian Secret service, and a secret important enough to kill for. Smiley continues to put together the pieces a step ahead or a step behind the Russian killers.