It is a beleaguered and betrayed Secret Service that has been put in the care of George Smiley. A mole has been uncovered at the organisation's highest levels - and its agents across the world put in grave danger. But untangling the traitor's web gives Smiley a chance to attack his Russian counterpart, Karla. And part-time spy Jerry Westerby is the weapon at Smiley's disposal.