Long retired since the war, Ailsa Brimley is now the editor of a small Christian magazine called "Christian Voice". The magazine's membership is small but loyal, and many of its readers have been supporters of the magazine since its inception. Unexpectedly, Brimley receives a letter from a reader, Stella Rode, who claims that her husband, a public school junior master in the town of Carne, is plotting to kill her. Fearing for Stella's life, Brimley hunts down her former wartime colleague, the retired Circus spy George Smiley, and asks him to help. Smiley, who knows the brother of school teacher Terence Fielding, agrees to do what he can, but before he is able to intervene, learns that Rode has been murdered. Brimley, feeling a duty of care to Rode on account of her family's long history as magazine subscribers, asks Smiley to go down and see what he can do to help. Smiley agrees and goes down to Carne to find out what he can about Rode's situation.