Tinker, Tailor, Soldier, Spy

Retired espionage veteran George Smiley is called out on a top secret mission: to uncover a Soviet agent within MI6's echelons.

Retired from the 'Circus', George Smiley, former right-hand of the late Control, meets Ricky Tarr, a British agent who went AWOL, believe defected. Tarr tells of how a mission to Portugal led him to learning about the mole in the 'Circus'.

The investigation begins, with Peter Guillam burgling the archives for information, while Smiley visits an old comrade whose past knowledge could prove vital to locating the spy.

While Guillam and Tarr come under pressure, Smiley recounts his one meeting with the Soviet master spy Karla, who is undoubtedly running the spy inside MI6.

Smiley goes to meet Jim Prideaux who is now back in Britain having survived his experience in Czechoslovakia. His testimony and that of others sheds new light on the 'Testify' fiasco and source 'Merlin'.

Smiley confronts one of his suspects and gives him the results of his investigations, which could prove a considerable embarrassment to those concerned.