John Le Carré's Smiley's people

The bespectacled spymaster is once more called from retirement to come to the aid of the 'Circus'--and he returns with a vengeance. The murder of an emigre Soviet General who was also a British agent sends him digging into the past on a twisted trail across Europe that moves inexorably towards a final showdown with his old adversary Karla of Moscow Centre.