A mole and a mule...............his jeep..............................Pepe.....................the University of Maryland is across the street from 7600 Adelphi road...........a metro bus stop right in front of it.......tons of foriegn teachers....................phds...........................professors....................Chinese,...........Pakistani........spies...............................galore

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.