of Circus. Tarr tries to circumspectly call on Circus to arrange for Irina’s escape to the West, but she is instead taken back to Moscow, suggesting that there may indeed be a mole within Circus.

Lacon and Guillam ask Smiley to investigate Gerald’s identity. Lacon explains that “we can’t investigate because all the instruments of enquiry are in the Circus’s hands, perhaps in the mole Gerald’s.” Beneath Alleline are four top lieutenants, and all of them have access to Source Merlin. Toby Esterhase, Bill Haydon, and Roy Bland, alongside Percy Alleline, now run the Circus and are in charge of “Witchcraft.” Although Smiley initially refuses to search out the mole, he agrees when reminded of the Circus’s field agents. His only partner will be Guillam, and Smiley asks him to bring files out of the Circus for him. Meanwhile, Smiley begins to search out other ousted members of the Circus.

Connie Sachs had been a top researcher for the Circus. Now, however, she lives as an alcoholic spinster in retirement. When Smiley goes to visit her, she agrees to tell him her story. In particular, Smiley is curious about Polyakov, a name that was supplied to him by Tarr. Connie explains that she was always suspicious of Cultural Attaché Aleksey Aleksandrovich Polyakov, who works at the Soviet Embassy in London. However, her suspicions were dismissed by her higher-ups, and soon she was sacked. She still believes in Smiley—and in Bill Haydon, though she heard (like everyone at the Circus) that he had slept with Smiley’s wife. News of Ann’s infidelities never visibly shakes Smiley. Guillam’s work—taking files from the Circus—is more difficult, and he, unlike Smiley, is quite shaken by the time he delivers the files to Smiley. However, as Smiley looks through the files, he begins to piece together a theory. He also notices that the files that he is now looking over while searching for Gerald were previously looked over by Control.

Smiley eventually tracks down Jim Prideaux, who has by this time been repatriated to England in exchange for captured Russian spies. He now teaches French. From Jim, George learns more about Operation Testify. Although Operation Testify has been described as Control’s personal war against the Czechs, Jim explains that his true purpose was to speak to Stevcek, a highly placed official “on the military side,” in order to obtain information, possibly as short as a single word. Prideaux recalls Control’s suspicions. Control had narrowed the mole’s identity down to five people, and if Operation Testify ended up going poorly, Jim’s mission would be to communicate a message to him. They created a code around the children’s nursery rhyme “Tinker Tailor.” Alleline was the Tinker, Haydon the Taylor, Bland was the Soldier, Esterhase was the Poorman, and George Smiley had been the Beggarman. Even when told of his title, Smiley remains calm, saying only “was I now?” in response. When Prideaux was captured and interrogated, he meets the Russian spymaster, Karla. Smiley had once met Karla, and had offered him the chance to defect; however, the usually unflappable English spy found himself taken off guard by Karla’s cold demeanor. During his interrogation, Prideaux is likewise outmaneuvered by Karla, who had already known every aspect of Operation Testify. In fact, Karla only wanted to find out from Jim to what extent Control had narrowed down his search for the mole. Prideaux’s information is useful to Smiley, but when he returned to England, he explains that he was silenced by Toby Esterhase.

Smiley next arranges an interrogation with Esterhase. Esterhase realizes immediately that Smiley has backing from Lacon, and that his investigation has indeed shown Witchcraft to be unreliable. From him, Smiley learns how Source Merlin works. The information was brought to Alleline on the pretext that he would take over Control’s position and represent a group of spies to Whitehall. Over time, it was revealed that the supposed Russian defector was actually a group of defectors. Later, they passed word that they had managed to place a defector—Polyakov—in the Soviet Embassy. This, explains Smiley, is the true knot of the problem. Once Polyakov was placed in London, it would become nearly impossible to figure out which side had a highly placed mole in the other’s camp. Circus would be turned “inside out.” From Esterhase, Smiley finds out where the English spies meet with Polyakov, sets up recording equipment, and then plants a message that he knows only the mole Gerald would bring to Polyakov. The person that arrives is Bill Haydon, who is taken into custody.

Haydon agrees to talk only to Smiley. He begins to explain that “The United States is no longer capable of undertaking its own revolution” and “the political posture of the United Kingdom is without relevance or moral viability in world affairs.” Smiley finds himself listening to these declarations with a sense that these ideas are understandable. He reflects that it was the “tone, rather than the music, which alienated him.” He explains that he was also instructed by Karla to sleep with Smiley’s wife because she was the “last illusion of the illusionless man” in order to give Smiley a sense of uncertainty about his feelings for his longtime friend, Bill Haydon. The only thing that Haydon seems to regret is having betrayed his friend Jim Prideaux, though he points out that he managed to arrange for the exchange that brought Prideaux back to England. Before Haydon’s own exchange is organized, he is killed while in captivity. Though it is not clear who shot Haydon, the closing scene of the novel is told from the point of view of one of Prideaux’s students, Bill Roach. The child looks at Jim Prideaux, who now seems lost and distracted. The novel ends “the gun, Bill Roach had finally convinced himself, was after all a dream,” suggesting that Jim killed his longtime friend and betrayer.

The events of Tinker, Tailor, Soldier, Spy leave Circus once again reorganized. Alleline loses his position and Smiley is put in charge of the Circus. One character looks at Smiley, who everyone knows is a cuckolded husband, and reflects that although Smiley looks like a “flabby oak,” he is like that solitary tree that remains standing after a storm. Smiley, meanwhile, sees Ann one last time and reflects that she is “tall and puckish, extraordinarily beautiful, essentially another man’s woman.”