'Trust us, Niki,' said Ned - but with such an honest, reassuring smile that Landau had the feeling that Ned had been out there fighting for him somehow, and that things were on the verge of coming right.

They're going to offer me a job, he thought on the Monday. They're going to turn me into a spy like Barley.

They're trying to put it right about my father twenty years after his death, he thought on the Tuesday.

Then on the Wednesday morning, Sam the driver pressed his doorbell for the last time and everything came clear.

'Where is it today then, Sam?' Landau asked him cheerfully. 'The Bloody Tower?'

'Sing Sing,' said Sam, and they had a good laugh.

But Sam delivered him not to the Tower and not to Sing Sing either, but to the side- entrance of one of the very Whitehall ministries that Landau only eleven days earlier had attempted unsuccessfully to storm. The grey-eyed Brock guided him up a back staircase and disappeared. Landau entered a great room that looked on to the Thames. A row of men sat at a table facing him. To the left sat Walter with his tie set straight and his hair slicked down. To the right sat Ned. Both looked solemn. And between them, with his cuffed hands resting flat on the table and lines of refusal round his neat jaw, sat a younger, 'sharp-suited man whom Landau rightly assumed to be senior in rank to both of them, and who, as Landau later put it, looked as though he had stepped out of a different movie. He was sleek and tight-hipped and groomed for television. He was rich in more than money. He was forty and rising, but the worst thing about him was his innocence. He looked too young to be charged with adult crimes.

'My name's Clive,' he said in an underpowered voice. 'Come in, Landau. We've got a problem about what to do with you.'

And beyond Clive – beyond all of them, in fact – Niki Landau as an afterthought saw,me. Old Palfrey. And Ned saw him see me and Ned smiled and made a pleasant show of introducing us.

'Ah now, Niki, this is Harry,' he said untruthfully.

Nobody else had earned a trade description till then but Ned provided one for me: 'Harry's our in-house umpire, Niki. He makes sure everyone gets a fair deal.'

'Nice,' said Landau.

Which is where, in the history of the affair, I made my own modest entrance, as legal errand boy, as fixer and bit player, and pleaser, and finally as chronicler; now Rosencrantz, 'now Guildenstern, and just occasionally Palfrey.

And to take even more care of Landau there was Reg, who was big and ginger and reassuring. Reg led Landau to a dunce's chair at the centre of the room, then sat beside him on another. And Landau took to Reg at once, which was usual, for Reg was by trade a welfarer and his clients included defectors, grounded fieldmen and blown agents, and other men and women whose bonds to England might have worn a little thin if old Reg Wattle and his cosy wife Berenice had not been there to hold their hands.

'You've done a good job but we can't tell you why it's good, because that would be insecure,' Clive continued in his and voice when Landau was comfortably settled. 'Even the little you know is too much. And we can't let you wander round Eastern Europe with our secrets in your head. It's too dangerous. For you and the people involved. So while you've performed a valuable service for us, you've also become a -serious worry. If this were wartime, we could lock you up or shoot you or something. But it isn't, not officially.'

Somewhere on his prudent little journey to power, Clive had taught himself to smile. It was an unfair weapon to use on friendly people, rather like silence on the telephone. But Clive knew nothing of unfairness because he knew nothing of its opposite. As to passion, it was what you used when you needed to persuade people.

'After all, you could point the finger at some very important people, couldn't you?' he continued so quietly that everyone kept still to hear him. 'I know you wouldn't do that deliberately but when one's handcuffed to a radiator one doesn't have much choice. Not in the end.'

And when Clive thought he had scared Landau just enough he glanced to me, and nodded to me, and watched me while I opened up the pompous leather folder I had brought with me and handed Landau the long document I had prepared, of which the purport was that Landau renounce in perpetuity all travel behind the Iron Curtain, that he never leave the country without first advising Reg so many days in advance, the details to be arranged between the two of them, and that Reg should look after Landau's passport in order to prevent mishaps. And that he accept irrevocably into his life the rôle of Reg or whomever the authorities should appoint in Reg's place as confidant, philosopher and discreet arbiter of his affairs of every kind – including the ticklish problem of how to handle the taxation on the cashier's cheque attached, drawn on the Fulham branch of a very boring British bank, in the sum of a hundred thousand pounds.

And that, in order that he be regularly scared by Authority, he should present himself every six months to the Service's Legal Adviser, Harry, for a top-up on the subject of Secrecy – to old Palfrey, Hannah's sometime lover, a man so bowed by life that he can be safely charged with keeping others upright. And that further to the above and pursuant to it and consequent upon it, the whole matter relating to a certain Russian woman and to her friend's literary manuscript, and to th e' contents of said manuscript – however much or little he may have understood their import – and to the part played by a certain British publisher, be as of this moment solemnly declared void, dead, inoperative and expunged, henceforth and for all time. Amen.

There was one copy and it would live in my safe till it was shredded or fell apart of old age. Landau read it twice while Reg read it over his shoulder. Then Landau disappeared into his own thoughts for a while without much regard for who was watching him or who was willing him to sign and cease to be a problem. Because Landau knew that in, this instance he was the buyer, not the seller.

He saw himself standing at the window of his Moscow hotel room. He remembered how he had wished he could hang up his traveller's boots and settle to a less arduous life. And. the amusing notion came to him that his Maker must have taken him at his word and fixed things accordingly, Which to everyone's unease caused him to break out in a little burst of laughter.

'Well I hope old Johnny the Yank is footing the bill for this, Harry,' he said.

But the joke did not receive the applause it deserved, since it happened to be true. So Landau took Reg's pen and signed, and handed me the document and watched me add my own signature as a witness, Horatio B. dePalfrey, which after twenty years has such a practised illegibility that if I had signed it Heinz's Tomato Soup- neither Landau nor anybody else could have told the difference, and put it back inside its leather coffin and patted down the lid. There was handshaking, mutual assurances were exchanged, and Clive murmured, 'We're grateful to you, Niki,'just like in the movie that Landau periodically convinced himself he was part of.

Then everybody shook Landau's hand yet again and, having watched him ride nobly into tile sunset or more accurately walk jauntily off down the corridor chatting away at Reg Wattle, who was twice his size, they waited fretfully for the 'take' on the intercepts for which I had already obtained the warrants under the infallible plea of intense American interest.

They tapped his office and home telephones, read his mail and fitted an electronic limpet to the rear axle of his beloved drop-head Triumph.

They followed him in his leisure hours and recruited a typist in his office to keep an eye on him as a 'suspect foreigner' while he served out the last weeks of his notice.

They put potential lady-friends alongside him in the bars where he liked to do his hunting. Yet despite these cumbersome and needless precautions, dictated by that same intense American interest, they drew a blank. No hint of bragging or indiscretion reached their ears. Landau never complained, never boasted, never attempted to go public. He became, in fact, one of the few finished and perfectly happy short stories of the trade.

He was the perfect prologue. He never came back.

He never attempted to get in touch with Barley Scott Blair, the great British spy. He lived in awe of him for ever. Even for the grand opening of the video shop, when he would have loved more than anything in the world to bask in the presence of this real-life secret British hero, he never tried to stretch the rules. Perhaps it was satisfaction enough for him to know that one night in Moscow, when the old country had called on him, he too had behaved like the English gentleman he sometimes longed to be. Or perhaps the Pole in him was content to have cocked a snook at the Russian bear next door. Or perhaps it was the memory of Katya that kept him faithful, Katya the strong, the virtuous, Katya the brave and beautiful, who even in her own fear had taken care to warn him of the dangers to himself. 'You must believe in what you are doing.'

And Landau had believed. And Landau was proud as Punch that he had, as any of us should be.

Even his video shop flourished. It was a sensation. A little rich for some people's blood now and then, including that of the Golders Green police, with whom I had to have a friendly word. But for others pure balm.

Above all, we were able to love him, because he saw us as we wished to be seen, as the omniscient, capable and heroic custodians of our great nation's inner health. It was a view of us that Barley never quite seemed able to share -any more, I have to say, than Hannah could, though she only ever knew it from outside, as the place to which she could not follow me, as the shrine-of ultimate compromise and therefore, in her unrelenting view, despair.

'They are definitely not the cure, Palfrey,' she had told me only a few weeks before, when for some reason I was trying to extol the Service. 'And they sound to me more likely to be the disease.'