chunk: Tarr tells Smiley that, on a mission to Istanbul, he had had an affair with Irina, a Soviet agent. She wanted to reveal the name of a mole in the top ranks of the Circus, but when Tarr reported this to London, they ignored him and ordered him straight home, whereas Moscow immediately kidnapped Irina. Tarr concluded that the mole had intercepted his message, and went into hiding, suspected of defecting and murdering the British station chief. Smiley sends Guillam to steal the Circus logbook for the night Tarr called: he finds the pages for that night are cut out, suggesting that Tarr's story is true.
  Smiley interviews Prideaux, who after brutal interrogation was exchanged by the Soviets but sacked from the service. Prideaux says the purpose of the mission to Hungary was to get the name of the mole. Control had codenamed the suspects "Tinker" (Alleline), "Tailor" (Haydon), "Soldier" (Bland), "Poorman" (Esterhase), and "Beggarman" (Smiley himself).