Sunny side eggs..............................Green Eggs and Ham......Sam i am......................sunny, happy faces.............Smiley..............Jims and Bills........my "family"..........

Plot

It is 1973, the height of the Cold War. George Smiley, former senior official of Britain's Secret Intelligence Service (known as "the Circus" because its London office is at Cambridge Circus), has been living in unhappy retirement for a year after an operation in Czechoslovakia, codenamed Testify, ended in disaster with the capture and torture of agent Jim Prideaux. The failure resulted in the dismissals of Smiley and his superior, Control, the head of the Circus.
Smiley is unexpectedly approached by Peter Guillam, his former protege at the Circus, and Under-Secretary Oliver Lacon, the Civil Service officer responsible for overseeing the Circus. At Lacon's home they meet with Ricki Tarr, a Circus agent who had been missing for months and had been declared persona non grata upon suspicion of having defected to Moscow. Tarr tells them of the existence of a Soviet mole at the highest level of the Circus. The mole is codenamed Gerald and is handled by Moscow Centre's agent, Polyakov, stationed at the Soviet embassy in London. Tarr tells them that when he obtained this information from a female Russian diplomat visiting Hong Kong and informed London, the woman was forcibly returned to Moscow. Tarr, realising someone in London had betrayed him, went on the run, eventually coming out to contact his former boss Guillam, the only person in the Circus he could trust.