George Smiley is one of the most brilliantly realised characters in British fiction. Bespectacled, tubby, eternally middle-aged, and deceptively ordinary, he has a mind like a steel trap and is said to possess 'the cunning of Satan and the conscience of a virgin'. Miss Ailsa Brimley is in a quandary. She's received a peculiar letter from Mrs Stella Rode, saying that she fears her husband – an assistant master at Carne School - is trying to kill her. Reluctant to go to the police, Miss Brimley calls upon her old wartime colleague, George Smiley.

Mr George Smiley is small, podgy, and at best, middle-aged. He is disillusioned, wrestles with idleness, and has been deserted by his beautiful wife. He is also compassionate, ruthless, and a senior British intelligence officer in short-lived retirement from the Circus, the British Secret Service organisation situated in London. But Moscow centre has infiltrated a mole into the Circus, and it's more than likely the perpetrator is Karla, Smiley's old adversary and his opposite number in Moscow.

It is the third summer of perestroika. Niki Landau, philanderer and travelling rep, attends the first Moscow audio fair and is asked by beautiful young Katya to take a parcel back to England. It’s addressed to Barley Blair, jazz-player and drinker, and contains information vital to the defence of the West. But times and heroes are changing. And Barley Blair is a man who makes his own rules of engagement.

Magnus Pym, counsellor at the British Embassy in Vienna, has suddenly vanished, believed defected. The chase is on for a missing husband, a devoted father, and a life-time secret agent. Pym's life, it is revealed, is entirely made up of secrets. The race is on to find the perfect spy.

The British Embassy in Bonn is up in arms. Her Majesty's financially troubled government is seeking admission to Europe's Common Market just as anti-British factions are rising to power in Germany. Rioters are demanding reunification, and the last thing the Crown can afford is a scandal. Then Leo Harting - an embassy nobody - goes missing with a case full of confidential files. London sends Alan Turner to control the damage, but he soon realises that neither side really wants Leo found - alive.