chunk: Smiley is brought out of retirement by Oliver Lacon, the civil servant in charge of intelligence, to investigate a claim by Ricki Tarr, a British spy, that there has been a long-term mole in a senior role in the Circus, as Control had suspected. Smiley chooses a trustworthy agent, Peter Guillam, and retired Special Branch officer Mendel to help him. He interviews Connie Sachs, who was sacked by Alleline after deducing that Alexei Polyakov, a Soviet cultural attaché in London, was a spy.