'And the safety signal?' Smiley asked. 'The signal that says "I am not being followed?" '

'Was Hamburg newspaper from yesterday,' Villem replied swiftly - but on this subject, he confessed, he had had a small difference with Vladimir, despite all the respect he owed to him as a leader, as a General, and as his father's friend.

'He tell to me, "Villem, you carry that newspaper in your pocket." But I tell to him : "Vladi, please, look at me, I have only track suit, no pockets." So he say, "Villem, then carry the newspaper under your arm." '

'Bill,' Stella breathed, with a sort of awe. 'Oh Bill, you stupid bloody fool.' She turned to Smiley. 'I mean, why didn't they just put it in the bloody post, whatever it is, and be done with it?'

Because it was a negative, and only negatives are acceptable by Moscow Rules. Because the General had a terror of betrayal, Smiley thought. The old boy saw it everywhere, in everyone around him. And if death is the ultimate judge, he was right.

'And it worked?' Smiley said finally to Villem with great gentleness. 'The hand-over worked?'

'Sure! It work fine,' Villem agreed heartily, and darted Stella a defiant glance

'And did you have any idea, for instance, who might have been your contact at this meeting?'

Then with much hesitation, and after much prompting, some of it from Stella, Villem told that also : about the hollowed face that had looked so desperate and had reminded him of his father; about the warning stare which was either real or he had imagined it because he was so excited. How sometimes, when he watched football on the television, which he liked to do very much, the camera caught someone's face or expression, and it stuck in your memory for the rest of the match, even if you never saw it again - and how the face on the steamer was of this sort exactly. He described the flicked horns of hair, and with his fingertips he lightly drew deep grooves in his own unmarked cheeks. He described the man's smallness, and even his sexiness - Villem said he could tell. He described his own feelings of being warned by the man, warned to take care of a precious thing. Villem would look the same way himself - he told Stella with a sudden flourish of imagined tragedy - if there was another war, and fighting, and he had to give away Beckie to a stranger to look after! And this was the cue for more tears, and more reconciliation, and more lamentations about the old man's death, to which Smiley's next question inevitably contributed.

'So you brought the yellow envelope back, and yesterday when the General came down with Beckie's duck, you handed him the envelope,' he suggested, as mildly as he knew how, but it was still some while before a plain narrative emerged.

It was Villem's habit, he said, before driving home on Fridays, to sleep at the depot for a few hours in the cab, then shave and drink a cup of tea with the boys so that he arrived home feeling steady, rather than nervous and bad-tempered. It was a trick he had learned from the older hands, he said : not to rush home, you only regret it. But yesterday was different, he said, and besides - lapsing suddenly into monosyllabic nicknames - Stell had taken Beck to Staines to see her mum. So he for once came straight home, rang Vladimir and gave him the code word which they had agreed on in advance.

'Rang him where?' Smiley asked, softly interruping.

'At flat. He told me : "Phone me only at flat. Never at library. Mikhel is good man, but he is not informed." '

And, Villem continued, within a short time - he forgot how long -Vladimir had arrived at the house by minicab, a thing he had never done before, bringing the duck for Beck. Villem handed him the yellow envelope of snapshots and Vladimir took them to the window and very slowly, 'like they were sacred from a church, Max,' with his back to Villem, Vladimir held the negatives one after the other to the light till he apparently found the one he was looking for, and after that he went on gazing at it for a long time.

'Just one?' Smiley asked swiftly - his mind upon the two proofs again - 'One negative?'

'Sure.'

'One frame, or one strip?'

Frame : Villem was certain. One small frame. Yes, thirty-five millimetre, like his own Agfa automatic. No, Villem had not been able to see what it contained, whether writing or what. He had seen Vladimir, that was all.

'Vladi was red, Max. Wild in the face, Max, bright with his eyes. He was old man.'

'And on your journey,' Smiley said, interrupting Villem's story to ask this crucial question. 'All the way home from Hamburg, you never once thought to look?'

'Was secret, Max. Was military secret.'

Smiley glanced at Stella.

'He wouldn't,' she said in answer to his unspoken question. 'He's too straight.'

Smiley believed her.

Villem took up his story again. Having put the yellow envelope in his pocket, Vladimir took Villem into the garden and thanked him, holding Villem's hand in both of his, telling him that it was a great thing he had done, the best; that Villem was his father's son, a finer soldier even than his father - the best Estonian stock, steady, conscientious and reliable; that with this photograph they could repay many debts and do great damage to the Bolsheviks; that the photograph was a proof , a proof impossible to ignore. But of what, he did not say - only that Max would see it, and believe, and remember. Villem didn't quite know why they had to go into the garden but he supposed that the old man in his excitement had become scared of microphones, for he was already talking a lot about security.

'I take him to gate but not to taxi. He tell me I must not come to taxi. "Villem, I am old man," he say to me. We speak Russian. "Next week maybe I fall dead. Who cares? Today we have won great battle. Max will be greatly proud of us." '

Struck by the aptness of the General's last words to him, Villem again bounded to his feet in fury, his brown eyes smouldering. 'Was Soviets! ' he shouted. 'Was Soviet spies, Max, they kill Vladimir ! He know too much!'

'So do you,' said Stella, and there was a long and awkward silence. 'So do we all,' she added, with a glance at Smiley.

'That's all he said?' Smiley asked. 'Nothing else, about the value of what you had done, for instance? Just that Max would believe?'

Villem shook his head.

'About there being other proofs, for instance?'

Nothing, said Villem : no more.

'Nothing to explain how he had communicated with Hamburg in the first place, set up the arrangements? Whether others of the Group were involved? Please think.'

Villem thought, but without result.

'So who have you told this to, William, apart from me?' Smiley asked.

'Nobody! Max, nobody!'

'He hasn't had time,' said Stella.

'Nobody! On journey I sleep in cab, save ten pounds a night subsistence. We buy house with this money! In Hamburg I tell nobody ! At depot nobody !'

'Had Vladimir told anyone - anyone that you know of, that is?'

'From the Group nobody only Mikhel, which was necessary, but not all, even to Mikhel. I ask to him : "Vladimir, who knows I do this for you?" "Only Mikhel a very little," he say. "Mikhel lends me money, lends me photocopier, he is my friend. But even to friends we cannot trust. Enemies I do not fear, Villem. But friends I fear greatly." '

Smiley spoke to Stella : 'If the police do come here,' he said. 'If they do, they will only know that Vladimir drove down here yesterday. They'll have got on to the cab driver, as I did.'

She was watching him with her large shrewd eyes.

'So?' she asked.

'So don't tell them the rest. They know all they need. Any more could be an embarrassment to them.'

'To them or to you?' Stella asked.

'Vladimir came here yesterday to see Beckie and bring her a present. That's the cover story, just as William first told it. He didn't know you'd taken her to see your mother. He found William here, they talked old times and strolled in the garden. He couldn't wait too long because of the taxi, so he left without seeing you or his god-daughter. That's all there was.'

'Were you here?' Stella was still watching him.

'If they ask about me, yes. I came here today and gave you the bad news. The police don't mind that Villem belonged to the Group. It's only the present that matters to them.'

Smiley returned his attention to Villem. 'Tell me, did you bring anything else for Vladimir?' he asked. 'Apart from what was in the envelope? A present perhaps? Something he liked and couldn't buy himself?'

Villem concentrated energetically upon the question before replying. 'Cigarettes! ' he cried suddenly. 'On boat, I buy him French cigarettes as gift. Gauloises, Max. He like very much! "Gauloises Caporal, with filter, Villem." Sure!'

'And the fifty pounds he had borrowed from Mikhel?' Smiley asked.

'I give back. Sure.'

'All?' said Smiley.

'All. Cigarettes was gift. Max, I love this man.'

Stella saw him to the door and at the door he gently took her arm and led her a few steps into the garden out of earshot of her husband.

'You're out of date,' she told him. 'Whatever it is you're doing, sooner or later one side or the other will have to stop. You're like the Group.'

'Be quiet and listen,' said Smiley. 'Are you listening?'

'Yes.'

'William's to speak to no one about this. Whom does he like to talk to at the depot?'

'The whole world.'

'Well, do what you can. Did anybody else ring apart from Mikhel? A wrong-number call even? Ring - then ring off?'

She thought, then shook her head.

'Did anyone come to the door? Salesman, market researcher, religious evangelist. Canvasser. Anyone? You're sure?'

As she continued staring at him her eyes seemed to acquire real knowledge of him, and appreciation. Then again she shook her head, denying him the complicity he was asking for.

'Stay away, Max. All of you. Whatever happens, however bad it is. He's grown up. He doesn't need a vicar any more.'

She watched him leave, perhaps to make sure he really went. For a while as he drove, the notion of Vladimir's piece of negative film nestling in its box consumed him like hidden money whether it was still safe, whether he should inspect it or convert it, since it had been brought through the lines at the cost of life. But by the time he approached the river he had other thoughts and purposes. Eschewing Chelsea, he joined the northbound Saturday traffic, which consisted mainly of young families with old cars. And one motor-bike with a black side-car, clinging faithfully to his tail all the way to Bloomsbury.