'Just one minute, please,' Di Salis had made yet another ill-judged interruption. 'The date? When did all this happen, please? I must have dates!'

'Sixty-seven. Dad was almost retired, weren't you, Dad?'

The old man did not stir.

'All right, sixty-seven. What month? Be precise, please!'

He all but said 'be precise, woman', and he was making Connie seriously anxious. But when she again tried to restrain him, he ignored her.

'April,' Doris said after some thought. 'We'd just had Dad's birthday. That's why he brought the thousand quid for the church. He knew Dad wouldn't take it for himself because Dad didn't like the way Drake made his money.'

'All right. Good. Well done. April. So Nelson died pre-April sixty-seven. What details did Drake supply of the circumstances? Do you remember that?'

'None. No details. I told you. Dad asked, and he just said dead as if Nelson was a dog. So much for brotherly love. Dad didn't know where to look. It nearly broke his heart and there was Drake not giving a hoot. I have no brother. Nelson is dead. And Dad still praying for Nelson, weren't you, Dad?'

This time the old man spoke. With the dusk, his voice had grown considerably in force.

'I prayed for Nelson and I pray for him still,' he said bluntly. 'When he was alive I prayed that one way or another he would do God's work in the world. I believed he had it in him to do great things. Drake, he'd manage anywhere. He's tough. But the light of the door at the Lord's Life Mission would not have burned in vain, I used to think, if Nelson Ko succeeded in helping to lay the foundation of a just society in China. Nelson might call it Communism. Call it what he likes.

But for three long years your mother and I gave him our Christian love, and I won't have it said, Doris, not by you or anyone, that the light of God's love can be put out forever. Not by politics, not by the sword.' He drew a long breath, 'And now he's dead, I pray for his soul, same as I do for your mother's,' he said, sounding strangely less convinced. 'If that's popery, I don't care.'

Connie had actually risen to go. She knew the limits, she had the eye, and she was scared of the way di Salis was hammering on. But di Salis on the scent knew no limits at all.

'So it was a violent death, was it? Politics and the sword, you said. Which politics? Did Drake tell you that? Actual killings were relatively rare, you know. I think you're holding out on us!'

Di Salis also was standing, but at Mr Hibbert's side, and he was yapping these questions downward at the old man's white head as if he were acting in a Sarratt playlet on interrogation.

'You've been so very kind,' said Connie gushingly to Doris. 'Really we've all we could possibly need and more. I'm sure it will all go through with the knighthood,' she said, in a voice pregnant with message for di Salis. 'Now away we go and thank you both enormously.'

But this time it was the old man himself who frustrated her.

'And the year after, he lost his other Nelson too, God help him, his little boy,' he said. 'He'll be a lonely man, will Drake. That was his last letter to us, wasn't it, Doris? Pray for my little Nelson, Mr Hibbert, he wrote. And we did. Wanted me to fly over and conduct the funeral. I couldn't do it, I don't know why. I never much held with money spent on funerals, to be honest.'

At this, di Salis literally pounced: and with a truly

terrible glee. He stooped right over the old man, and he was so animated that he grabbed a fistful of shawl in his feverish little hand.

'Ah! Ah now! But did he ever ask you to pray for Nelson senior? Answer me that.'

'No,' the old man said simply. 'No, he didn't.'

'Why not? Unless he wasn't really dead, of course! There are more ways than one of dying in China, aren't there, and not all of them are fatal! Disgraced: is that a better expression?'

His squeaky words flew about the fire-lit room like ugly spirits.

'They're to go, Doris,' the old man said calmly to the sea. 'See that driver right, won't you, dear? I'm sure we should have taken out to him, but never mind.'

They stood in the hall, making their goodbyes.

The old man had stayed in his chair and Doris had closed the door on him. Sometimes, Connie's sixth sense was frightening.

'The name Liese doesn't mean anything to you, does it, Miss Hibbert?' she asked, buckling her enormous plastic coat. 'We have a reference to a Liese in Mr Ko's life.'

Doris's unpainted face made an angry scowl.

'That's Mum's name,' she said. 'She was German Lutheran. The swine stole that too, did he?'

With Toby Esterhase at the wheel, Connie Sachs and Doc di Salis hurried home to George with their amazing news. At first, on the way, they squabbled about di Salis's lack of restraint. Toby Esterhase particularly was shocked, and Connie seriously feared the old man might write to Ko. But soon the import of their discovery overwhelmed their apprehensions, and they arrived triumphant at the gates of their secret city.

Safely inside the walls, it was now di Salis's hour of glory. Summoning his family of yellow perils once more, he set in motion a whole variety of enquiries, which sent them scurrying all over London on one false pretext or another, and to Cambridge too. At heart di Salis was a loner. No one knew him, except Connie perhaps and, if Connie didn't care for him, then no one liked him either. Socially he was discordant and frequently absurd. But neither did anyone doubt his hunter's will.

He scoured old records of the Shanghai University of Communications, in Chinese the Chiao Tung - which had a reputation for student Communist militancy after the thirty-nine forty-five war - and concentrated his interest upon the Department of Marine Studies, which included both administration and ship-building in its curriculum. He drew lists of Party cadre members of both before and after forty-nine, and pored over the scant details of those entrusted with the takeover of big enterprises where technological knowhow was required: in particular the Kiangnan shipyard, a massive affair from which the Kuomintang elements had repeatedly to be purged. Having drawn up lists of several thousand names, he opened files on all those who were known to have continued their studies at Leningrad University and afterwards reappeared at the shipyard in improved positions. A course of shipbuilding at Leningrad took three years. By di Salis's computation, Nelson should have been there from fifty-three to fifty-six and afterwards formally assigned to the Shanghai municipal department in charge of marine engineering, which would then have returned him to Kiangnan. Accepting that Nelson possessed not only Chinese forenames which were still unknown, but quite possibly had chosen a new surname for himself into the bargain, di Salis warned his helpers that Nelson's biography might be split into two parts, each under a different name. They should watch for dovetailing. He cadged lists of graduates and lists of enrolled students both at Chiao Tung and at Leningrad and set them side by side. China-watchers are a fraternity apart, and their common interests transcend protocol and national differences. Di Salis had connections not only in Cambridge, and in every Oriental archive, but in Rome, Tokyo and Munich as well. He wrote to all of them, concealing his goal in a welter of other questions. Even the Cousins, it turned out later, had unwittingly opened their files to him. He made other enquiries even more arcane. He despatched burrowers to the Baptists, to delve among records of old pupils at the Mission Schools, on the off-chance that Nelson's Chinese names had, after all, been taken down and filed. He tracked down any chance records of the deaths of mid-ranking Shanghai officials in the shipping industry.

That was the first leg of his labours. The second began with what Connie called the Great Beastly Cultural Revolution of the mid-Sixties and the names of such Shanghainese officials who, in consequence of criminal pro-Russian leanings, had been officially purged, humiliated, or sent to a May 7th school to rediscover the virtues of peasant labour. He also consulted lists of those sent to labour reform camps, but with no great success. He looked for any references, among the Red Guards' harangues, to the wicked influence of a Baptist upbringing upon this or that disgraced official, and he played complicated games with the name of KO. It was at the back of his mind that, in changing his name, Nelson might have hit upon a different character which retained an internal kinship with the original -either homophonic or symphonetic. But when he tried to explain this to Connie, he lost her.

Connie Sachs was pursuing a different line entirely. Her interest centred on the activities of known Karla-trained talent-spotters working among overseas students at the University of Leningrad in the fifties; and on rumours, never proven, that Karla, as a young Comintern agent, had been lent to the Shanghai Communist underground after the war, to help them rebuild their secret apparatus.

It was in the middle of all this fresh burrowing that a small bombshell was delivered from Grosvenor Square. Mr Hibbert's intelligence was still fresh from the presses, in fact, and the researchers of both families were still frantically at work, when Peter Guillam walked in on Smiley with an urgent message. He was as usual deep in his own reading, and as Guillam entered he slipped a file into a drawer and closed it.

'It's the Cousins,' Guillam said gently. 'About Brother Ricardo, your favourite pilot. They want to meet with you at the Annexe as soon as possible. I'm to ring back by yesterday.'

'They want what?'

'To meet you. But they use the preposition.'

'Do they? Do they really? Good Lord. I suppose it's the German influence. Or it is old English? Meet with. Well I must say.' And he lumbered off to his bathroom to shave.

Returning to his own room, Guillam found Sam Collins sitting in the soft chair, smoking one of his beastly brown cigarettes and smiling his washable smile.

'Something up?' Sam asked, very leisurely.

'Get the hell out of here,' Guillam snapped.

Sam was in general nosing around a lot too much for Guillam's liking, but that day he had a firm reason for distrusting him. Calling on Lacon at the Cabinet Office to deliver the Circus's monthly imprest account for his inspection, he had been astonished to see Sam emerging from his private office, joking easily with Lacon and Saul Enderby of the Foreign Office.

Before the fall, studiously informal meetings of intelligence partners to the special relationship were held as often as monthly and followed by what Smiley's predecessor Alleline had liked to call 'a jar'. If it was the American turn to play host, then Alleline and his cohorts, among them the popular Bill Haydon, would be shepherded to a vast rooftop bar, known within the Circus as the planetarium, to be regaled with dry martinis and a view of West London they could not otherwise have afforded. If it was the British turn, then a trestle table was set up in the rumpus room, and a darned damask tablecloth spread over it, and the American delegates were invited to pay homage to the last bastion of clubland spying, and incidentally the birthplace of their own service, while they sipped South African sherry disguised by cut-glass decanters on the grounds that they wouldn't know the difference. For the discussions, there was no agenda and by tradition no notes were taken. Old friends had no need of such devices, particularly since hidden microphones stayed sober and did the job better.