Miss Ailsa Brimley is in a quandary. She's received a peculiar letter from Mrs. Stella Rode, saying that she fears her husband--an assistant master at Carne School--is trying to kill her. Reluctant to go to the police, Miss Brimley calls upon her old wartime colleague, George Smiley. Unfortunately, it's too late. Mrs. Rode has just been murdered. As Smiley takes up the investigation, he realizes that in life--as in espionage--nothing is quite what it appears.