'The United States is no longer capable of undertaking its own revolution...

'The political posture of the United Kingdom is without relevance or moral viability in world affairs...'

With much of it, Smiley might in other circumstances have agreed: it was the tone, rather than the music, which alienated him.

'In capitalist America economic repression of the masses is institutionalised to a point which not even Lenin could have foreseen.

'The cold war began in 1917 but the bitterest struggles lie ahead of us, as America's deathbed paranoia drives her to greater excesses abroad..."

He spoke not of the decline of the West, but of its death by greed and constipation. He hated America very deeply, he said, and Smiley supposed he did. Haydon also took it for granted that secret services were the only real measure of a nation's political health, the only real expression of its subconscious.

Finally he came to his own case. At Oxford, he said, he was genuinely of the right, and in the war, it scarcely mattered where one stood as long as one was fighting the Germans. For a while, after forty-five, he said, he had remained content with Britain's part in the world, till gradually it dawned on him just how trivial this was. How and when was a mystery. In the historical mayhem of his own lifetime he could point to no one occasion: simply he knew that if England were out of the game, the price of fish would not be altered by a farthing. He had often wondered which side he would be on if the test ever came; after prolonged reflection he had finally to admit that if either monolith had to win the day, he would prefer it to be the East.

'It's an aesthetic judgment as much as anything,' he explained, looking up. 'Partly a moral one, of course.'

'Of course,' said Smiley politely.

From then on, he said, it was only a matter of time before he put his efforts where his convictions lay.

That was the first day's take. A white sediment had formed on Haydon's lips, and he had begun weeping again. They agreed to meet tomorrow at the same time.

'It would be nice to go into the detail a little if we could, Bill,' Smiley said as he left.

'Oh and look, tell Jan, will you?' Haydon was lying on the bed, staunching his nose again. 'Doesn't matter a hoot what you say, long as you make it final.' Sitting up, he wrote out a cheque and put it in a brown envelope. 'Give her that for the milk bill.'

Realising perhaps that Smiley was not quite at ease with this brief, he added: 'Well, I can't take her with me, can I? Even if they let her come, she'd be a bloody millstone.'

The same evening, following Haydon's instructions, Smiley took a tube to Kentish Town and unearthed a cottage in an unconverted mews. A flat-faced fair girl in jeans opened the door to him; there was a smell of oil paint and baby. He could not remember whether he had met her at Bywater Street so he opened with: 'I'm from Bill Haydon. He's quite all right but I've got various messages from him.'

'Jesus,' said the girl softly. 'About bloody time and all.'

The living room was filthy. Through the kitchen door he saw a pile of dirty crockery and he knew she used everything until it ran out, then washed it all at once. The floorboards were bare except for long psychedelic patterns of snakes and flowers and insects painted all over them.

'That's Bill's Michelangelo ceiling,' she said conversationally. 'Only he's not going to have Michelangelo's bad back. Are you government?' she asked, lighting a cigarette. 'He works for government, he told me.' Her hand was shaking and she had yellow smudges under her eyes.

'Oh look, first I'm to give you that,' said Smiley, and delving in an inside pocket handed her the envelope with the cheque.

'Bread,' said the girl, and put the envelope beside her.

'Bread,' said Smiley, answering her grin, then something in his expression, or the way he echoed that one word, made her take up the envelope and rip it open. There was no note, just the cheque, but the cheque was enough: even from where Smiley sat, he could see it had four figures.

Not knowing what she was doing, she walked across the room to the fireplace and put the cheque with the grocery bills in an old tin on the mantelpiece. She went into the kitchen and mixed two cups of Nescafe, but she only came out with one.

'Where is he?' she said. She stood facing him. 'He's gone chasing after that snotty little sailor boy again. Is that it? And this is the pay-off, is that it? Well you bloody tell him from me...'

Smiley had had scenes like this before, and now absurdly the old words came back to him.

'Bill's been doing work of national importance. I'm afraid we can't talk about it, and nor must you. A few days ago he went abroad on a secret job. He'll be away some while. Even years. He wasn't allowed to tell anyone he was leaving. He wants you to forget him. I really am most awfully sorry.'

He got that far before she burst out. He didn't hear all she said, because she was blurting and screaming, and when the baby heard her it started screaming too, from upstairs. She was swearing, not at him, not even particularly at Bill, just swearing dry-eyed and demanding to know who the hell, who the bloody bloody hell believed in government any more? Then her mood changed. Round the walls, Smiley noticed Bill's other paintings, mainly of the girl: few were finished, and they had a cramped, condemned quality by comparison with his earlier work.

'You don't like him, do you? I can tell,' she said. 'So why do you do his dirty work for him?'

To this question also there seemed no immediate answer. Returning to Bywater Street, he again had the impression of being followed, and tried to telephone Mendel with the number of a cab which had twice caught his eye, asking him to make immediate enquiries. For once, Mendel was out till after midnight: Smiley slept uneasily and woke at five. By eight he was back at Sarratt, to find Haydon in festive mood. The inquisitors had not bothered him; he had been told by Craddox that the exchanges had been agreed and he should expect to travel tomorrow or the next day. His requests had a valedictory ring; the balance of his salary and the proceeds of any odd sales made on his behalf should be forwarded to him care of the Moscow Narodny Bank, who would also handle his mail. The Arnolfini Gallery in Bristol had a few pictures of his, including some early watercolours of Damascus, which he coveted. Could Smiley please arrange? Then, the cover for his disappearance.

'Play it long,' he advised. 'Say I've been posted, lay on the mystery, give it a couple of years then run me down...'

'Oh I think we can manage something, thank you,' Smiley said. For the first time since Smiley had known him, Haydon was worried about clothes. He wanted to arrive looking like someone, he said: first impressions were so important. 'Those Moscow tailors are unspeakable. Dress you up like a bloody beadle.'

'Quite,' said Smiley, whose opinion of London tailors was no better.

Oh and there was a boy, he added carelessly, a sailor friend, lived in Notting Hill. 'Better give him a couple of hundred to shut him up. Can you do that out of the reptile fund?'

'I'm sure.'

He wrote out an address. In the same spirit of good fellowship, Haydon then entered into what Smiley had called the details.

He declined to discuss any part of his recruitment nor of his lifelong relationship with Karla. 'Lifelong?' Smiley repeated quickly. 'When did you meet?' The assertions of yesterday appeared suddenly nonsensical, but Haydon would not elaborate.

From about nineteen fifty onwards, if he was to be believed, Haydon had made Karla occasional selected gifts of intelligence. These early efforts were confined to what he hoped would discreetly advance the Russian cause over the American; he was 'scrupulous not to give them anything harmful to ourselves' as he put it, or harmful to our agents in the field.

The Suez adventure in fifty-six finally persuaded him of the inanity of the British situation and of the British capacity to spike the advance of history while not being able to offer anything by way of contribution. The sight of the Americans sabotaging the British action in Egypt was, paradoxically, an additional incentive. He would say therefore that from fifty-six on, he was a committed, full-time Soviet mole with no holds barred. In sixty-one he formally received Soviet citizenship, and over the next ten years two Soviet medals - quaintly, he would not say which, though he insisted that they were 'top stuff'. Unfortunately, overseas postings during this period limited his access; and since he insisted on his information being acted upon wherever possible - 'rather than being chucked into some daft Soviet archive' - his work was dangerous as well as uneven. With his return to London, Karla sent him Polly (which was evidently the house name for Polyakov) as a helpmate, but Haydon found the constant pressure of clandestine meetings difficult to sustain, particularly in view of the quantity of stuff he was photographing.

He declined to discuss cameras, equipment, pay or trade-craft during this pre-Merlin period in London, and Smiley was conscious all the while that even the little Haydon was telling him was selected with meticulous care from a greater, and perhaps somewhat different truth. Meanwhile both Karla and Haydon were receiving signals that Control was smelling a rat. Control was ill, of course, but clearly he would never willingly give up the reins while there was a chance that he was making Karla a present of the service. It was a race between Control's researches and his health. Twice, he had very nearly struck gold - again, Haydon declined to say how - and if Karla had not been quick on his feet, the mole Gerald would have been trapped. It was out of this nervy situation that first Merlin, and finally Operation Testify, were born. Witchcraft was conceived primarily to take care of the succession: to put Alleline next to the throne, and hasten Control's demise. Secondly, of course, Witchcraft gave Centre absolute autonomy over the product flowing into Whitehall. Thirdly - and in the long run most important, Haydon insisted - it brought the Circus into position as a major weapon against the American target. 'How much of the material was genuine?' Smiley asked.

Obviously the standard varied according to what one wanted to achieve, said Haydon. In theory, fabrication was very easy: Haydon had only to advise Karla of Whitehall's areas of ignorance and the fabricators would write for them. Once or twice, for the hell of it, said Haydon, he had written the odd report himself. It was an amusing exercise to receive, evaluate and distribute one's own work. The advantages of Witchcraft in terms of tradecraft were of course inestimable. It placed Haydon virtually out of Control's reach, and gave him a cast-iron cover story for meeting Polly whenever he wished. Often months would pass without their meeting at all. Haydon would photograph Circus documents in the seclusion of his room - under cover of preparing Polly's chickenfeed - hand it over to Esterhase with a lot of other rubbish and let him cart it down to the safe house in Lock Gardens.