In the final part of John le Carre's classic story, George Smiley's search for the mole at the heart of the Circus finally comes to an end.

Smiley's investigation to snare the traitor at the heart of the Circus leads him to Jerry Westerby, a Fleet Street journalist.

Smiley thinks that the time has come to call on Jim Prideaux, whose assignment to Czechoslovakia went disastrously wrong, with the mole at the heart of the Circus to blame.

Smiley recalls the past - his involvement with Tinker, Tailor, Soldier and Poorman, and Karla - the legendary head of Moscow Circus.

In his search for the mole sitting at the heart of the Circus, Smiley sets out for Oxford to visit an invaluable friend.

Smiley is forced to go back over some very old ground when he is told a story about spies.

Was George Smiley sacked after a scandal or is he merely retired? When he is summoned by the Cabinet watchdog for Intelligence Affairs, Smiley agrees to head the hunt for a Secret Service mole.