Time did not kill the rumours. To the contrary they multiplied, taking colour from his isolation and calling it obsession.

It was remembered that Bill Haydon had not merely been George Smiley's colleague, but Ann's cousin and something more besides. Smiley's fury against him, they said, had not stopped at Haydon's death: he was positively dancing on Bill's grave. For example, George had personally supervised the clearing of Haydon's fabled pepper-pot room overlooking the Charing Cross Road, and the destruction of every last sign of him, from his indifferent oil-paintings by his own hand to the leftover oddments in the drawers of his desk; even the desk itself, which he had ordered sawn up, and burned. And when that was done, they maintained, he had called in Circus workmen to tear down the partition walls. Oh yes, said Martindale.

Or, for another example, and frankly a most unnerving one, take the photograph which hung on the wall of Smiley's dingy, throne-room, a passport photograph by the look of it, but blown up far beyond its natural size, so that it had a grainy and some said spectral look. One of the Treasury boys spotted it during an ad-hoc conference about scrapping the operational bank accounts.

'Is that Control's portrait by the by?' he had asked of Peter Guillam, purely as a bit of social chit chat. No sinister intent behind the question. Well, surely one was allowed to ask? Control, other names still unknown, was the legend of the place. He had been Smiley's guide and mentor for all of thirty years. Smiley had actually buried him, they said: for the very secret, like the very rich, have a tendency to die unmourned.

'No, it bloody well isn't Control,' Guillam the cupbearer had retorted, in that off-hand, supercilious way of his. 'It's Karla.'

And who was Karla when he was at home?

Karla, my dear, was the workname of the Soviet case officer who had recruited Bill Haydon in the first place, and had the running of him thereafter. 'A different sort of legend entirely, to say the least,' said Martindale, all aquiver. 'It seems we've a real vendetta on our hands. How puerile can you get, I wonder?'

Even Lacon was a mite bothered by that picture.

'Now seriously, why do you hang him there, George?' he demanded, in his bold, head-prefect's voice, dropping in on Smiley one evening on his way home from the Cabinet Office. 'What does he mean to you, I wonder? Have you thought about that one? It isn't a little macabre, you don't think? The victorious enemy? I'd have thought he would get you down, gloating over you all up there?'

'Well, Bill's dead,' said Smiley, in that elliptical way he had sometimes of giving a clue to an argument, rather than the argument itself.

'And Karla's alive, you mean?' Lacon prompted. 'And you'd rather have a live enemy than a dead one? Is that what you mean?'

But questions of George Smiley at a certain point had a habit of passing him by; even, said his colleagues, of appearing to be in bad taste.

An incident which provided more substantial fare around the Whitehall bazaars concerned the 'ferrets', or electronic sweepers. A worse case of favouritism could not be remembered anywhere. My God those hoods had a nerve sometimes! Martindale, who had been waiting a year to have his room done, sent a complaint to his Under-Secretary. By hand. To be opened personally by. So did his Brother-in-Christ at Defence and so, nearly, did Hammer of Treasury, but Hammer either forgot to post his, or thought better of it at the last moment. It wasn't just a question of priorities, not at all. Not even of principle. Money was involved. Public money. Treasury had already had half the Circus rewired on George's insistence. His paranoia about eavesdropping knew no limits, apparently. Add to that, the ferrets were short-staffed, there had been industrial disputes about unsocial hours - oh, any number of angles! Dynamite, the whole subject.

Yet what had happened in the event? Martinale had the details at his manicured fingertips. George went to Lacon on a Thursday - the day of the freak heatwave, you remember, when everyone practically expired, even at the Garrick -and by the Saturday - a Saturday, - imagine the overtime! - the brutes were swarming over the Circus, enraging the neighbours with their din, and tearing the place apart. A more gross case of blind preference had not been met with since -since, well, they allowed Smiley to have back that mangy old Russian researcher of his, Sachs, Connie Sachs, the don woman from Oxford, against all reason, calling her a mother when she wasn't.

Discreetly, or as discreetly as he could manage, Martindale went to quite some lengths to find our whether the ferrets had actually discovered anything, but met a blank wall. In the secret world, information is money, and by that standard at least, though he might not know it, Roddy Martindale was a pauper, for the inside to this inside-story was known only to the smallest few. It was true that Smiley called on Lacon in his panelled room overlooking St James's Park on the Thursday: and that the day was uncommonly hot for autumn. Rich shafts of sunlight poured on to the representational carpet, and the dust-specks played in them like tiny tropical fish. Lacon had even removed his jacket, though of course not his tie.

'Connie Sachs has been doing some arithmetic on Karla's handwriting in analogous cases,' Smiley announced.

'Handwriting?' Lacon echoed, as if handwriting were against the regulations.

'Tradecraft. Karla's habits of technique. It seems that where it was operable, he ran moles and sound-thieves in tandem.'

'Once more now in English, George, do you mind?'

Where circumstances allowed, said Smiley, Karla had liked to back up his agent operations with microphones. Though Smiley was satisfied that nothing had been said within the building which could compromise any 'present plans' as he called them, the implications were unsettling.

Lacon was getting to know Smiley's handwriting too.

'Any collateral for that rather academic theory?' he enquired, examining Smiley's expressionless features over the top of his pencil, which he held between his two index fingers, like a rule.

'We've been making an inventory of our own audio stores,' Smiley confessed with a puckering of his brow. 'There's a quantity of house equipment missing. A lot seems to have disappeared during the alterations of sixty-six.' Lacon waited, dragging it out of him. 'Haydon was on the building committee responsible for having the work carried out,' Smiley ended, as a final sop. 'He was the driving force, in fact. It's just - well, if the Cousins ever got to hear of it, I think it would be the last straw.'

Lacon was no fool, and the Cousins' wrath just when everyone was trying to smooth their feathers was a thing to be avoided at any cost. If he had had his way, he would have ordered the ferrets out the same day. Saturday was a compromise and without consulting anybody he despatched the entire team, all twelve of them, in two grey vans painted 'Pest Control'. It was true that they tore the place apart, hence the silly rumours about the destruction of the pepper-pot room. They were angry because it was the weekend, and perhaps therefore needlessly violent: the tax paid on overtime was frightful. But their mood changed fast enough when they bagged eight radio microphones in the first sweep, every one of them Circus standard-issue from audio stores. Haydon's distribution of them was classic, as Lacon agreed when he called to make his own inspection. One in a drawer of a disused desk, as if innocently left there and forgotten about, except that the desk happened to be in the coding room. One collecting dust on top of an old steel cupboard in the fifth-floor conference room - or, in the jargon, rumpus room. And one, with typical Haydon flair, wedged behind the cistern in the senior officers' lavatory next door. A second sweep, to include load-bearing walls, threw up three more embedded in the fabric during the building work. Probes, with plastic snorkel-straws to pipe the sound back to them. The ferrets laid them out like a game-line. Extinct, of course, as all the devices were, but put there by Haydon nevertheless, and tuned to frequencies the Circus did not use.

'Maintained at Treasury cost, too, I declare,' said Lacon, with the driest of smiles, fondling the leads which had once connected the probe microphones with the mains power supply. 'Or used to be, till George rewired the place. I must be sure to tell Brother Hammer. He'll be thrilled.'

Hammer, a Welshman, being Lacon's most persistent enemy.

On Lacon's advice Smiley now staged a modest piece of theatre. He ordered the ferrets to reactivate the radio microphones in the conference room and to modify the receiver on one of the Circus's few remaining surveillance cars. Then he invited three of the least bending Whitehall desk jockeys, including the Welsh Hammer, to drive in a half-mile radius round the building, while they listened to a pre-scripted discussion between two of Smiley's shadowy helpers sitting in the rumpus room. Word for word. Not a syllable out of place.

After which, Smiley himself swore them to absolute secrecy, and for good measure made them sign a declaration, drafted by the housekeepers expressly to inspire awe. Peter Guillam reckoned it would keep them quiet for about a month.

'Or less if it rains,' he added sourly.

Yet if Martindale and his colleagues in the Whitehall outfield lived in a state of primeval innocence about the reality of Smiley's world, those closer to the throne felt equally removed from him. The circles around him grew smaller as they grew nearer, and precious few in the early days reached the centre. Entering the brown and dismal doorway of the Circus, with its temporary barriers manned by watchful janitors, Smiley shed none of his habitual privacy. For nights and days at a time, the door to his tiny office suite stayed closed and his only company was Peter Guillam, and a hovering dark-eyed factotum named Fawn, who had shared with Guillam the job of babysitting Smiley during the smoking-out of Haydon. Sometimes Smiley disappeared by the back door with no more than a nod, taking Fawn, a sleek, diminutive creature, with him and leaving Guillam to field the phone calls and get hold of him in emergency. The mothers likened his behaviour to the last days of Control, who had died in harness, thanks to Haydon, of a broken heart. By the organic processes of a closed society, a new word was added to the jargon. The unmasking of Haydon now became the fall and Circus history was divided into before the fall and after it. To Smiley's coming and goings, the physical fall of the building itself, three-quarters empty and, since the visit of the ferrets, in a wrecked condition, lent a sombre sense of ruin which at low moments became symbolic to those who had to live with it. What the ferrets destroy they do not put together: and the same, they felt perhaps, was true of Karla, whose dusty features, nailed there by their elusive chief, continued to watch over them from the shadows of his Spartan throne-room.