'Even if we go back years and years?' said Bret.

'Especially if we go back years and years,' I said. 'She was my wife. I was in love with her.'

'No suspicions. None at all?'

'She'd been cleared by the department. She'd been cleared by Internal Security. She had been vetted regularly…'

'Touché,' said Bret. Frank Harrington nodded to no one in particular but didn't smile.

'If you're making notes,' I told Bret, 'make a note of that. My failure was no greater than the department's failure.'

Bret shook his head. 'Don't be stupid, Bernard. She was your wife. You brought her to me and suggested that I gave her a job. You were married to her for twelve years. She's the mother of your children. How can you compare your failure to know what she truly was with ours?'

'But finally I did know,' I said. 'If I hadn't flushed her out she'd still be working here, and still be passing your secrets back to Moscow.'

'Our secrets,' said Bret Rensselaer. 'Let's rather say our secrets, unless you are thinking of leaving us too.'

I said, 'That's a bloody offensive thing to say, Bret.'

'Then I withdraw it,' said Bret. 'I'm not trying to make life more difficult for you, Bernard, really I'm not.' He moved his small pages about on the desk. 'You didn't ever hear any phone conversations, or find correspondence which, in the light of what we know now, has a bearing on your wife's defection?'

'Do you think I wouldn't have said so. You must have read the transcript of my formal interview. It's all there.'

'I know it is, Bernard, and I've already apologized for going through all this once more. But that interview was for Internal Security. This is to go on your report.' Each year a report on every member of the staff was filed to the Personnel Department by his or her immediate superior. The fact that Bret was completing mine this year was just another sign of the way he was edging into Dicky Cruyer's department.

'To go on my report?'

'Well, you didn't imagine we'd be able to overlook your wife's defection, did you? I'm supposed to report on your… ' A glance down at his notes. '… judgement, political sense, power of analysis and foresight. Almost every report has some sort of mention of an employee's wife, Bernard. There is nothing special about that. The whole British Civil Service has exactly the same system of reports, so don't get paranoid.'

Frank finished filling his pipe. He leaned back and said, 'The department looks after its own, Bernard. I don't have to tell you that.' He still hadn't lit his pipe, but he put it into his mouth and chewed at the stem of it.

I said, 'I don't think I know what you're talking about, Frank.'

Frank Harrington had spent a long time in the department, and this gave him certain privileges, so that now he didn't defer to Bret Rensselaer despite Bret's senior ranking. 'I'm trying to explain to you that Bret and I want this to come out well for you, Bernard.'

'Thanks, Frank,' I said, without much warmth.

'But it's got to look right on paper too,' said Bret. He stood up, put his hands in his pockets and jingled his small change.

'And how does it look on paper now?' I said. 'Without you and Frank putting all your efforts into making it come out well for me.'

Bret looked at Frank with a pained expression in his eyes. He was practising that look, so that he could turn it on me if I continued to be insubordinate. Bret was standing by the window. He looked at the view across the park and without turning round said, 'The department's got a lot of enemies, Bernard. Not only certain socialist Members of Parliament. The Palace of Westminster has plenty of publicity hounds who'd love to get hold of something like this so they could pontificate on 'Panorama', get a few clips on TV news and be interviewed on "Newsnight". And there are many of our colleagues in Whitehall who always enjoy the sight of us wriggling under the microscope.'

'What is it we're trying to hide, Bret?' I asked.

Bret rounded on me angrily. 'For Christ's sake…' He went across the room, picked up his jacket and draped it over his arm. 'Talk to him, Frank,' he said. 'I'm stepping outside for a moment. See if you can talk some sense into the man, will you?'

Frank said nothing. He held the unlit pipe in his teeth for a moment before taking it from his mouth and staring at the tobacco. It was something to do while Bret Rensselaer went out and closed the door. Even then Frank took his time before saying, 'We've known each other a long time.'

That's right,' I said.

'Berlin: 1945. You were just beginning to walk. You were living at the top of Frau Hennig's house. Your father was one of the first officers to get his family out to occupied Germany. I was touched by that, Bernard. So many of the other chaps preferred to be away from their families. They had the plush life of the conqueror. Big apartments, servants, booze, women – everything was available for a few cigarettes or a box of rations. But your father was an exception, Bernard. He wanted you and your mother there with him, and he moved heaven and hell to get you over there. I liked him for that, Bernard. And for much more.'

'What is it you want to tell me, Frank?'

'This business with your wife was a shock. It was a shock for you, and a shock for me. The whole department was caught napping, Bernard, and they are still smarting from the blow.'

'And blaming me? So that's it?'

'No one's blaming you, Bernard. As you told Bret just now, you're the one who tipped us off. No one can blame you.'

'But… Can I hear a "but" coming?'

Frank fiddled with his pipe. 'Let's talk about this chap Stinnes,' he said. 'He was the officer who arrested you in East Berlin at the time of your wife's defection?'

'Yes,' I said.

'And he was the interrogation officer too?'

'I've been through all that with you, Frank,' I said. 'There was no proper interrogation. He'd had orders from Moscow to wait for Fiona to arrive.'

'Yes, I remember,' said Frank. 'The point I'm making is that Stinnes is a senior officer with the KGB's Berlin office.'

'No doubt about that,' I agreed.

'Your wife is now working for the KGB in that same office?'

'The current guess is that she's in charge of it,' I said.

'And Stinnes is certain to be one of her senior staff members, wouldn't you say?'

'Of course.'

'So Stinnes is the one person who knows about your wife's defection and her present occupation. It's even possible that he was concerned with her debriefing.'

'Don't keep going round and round in circles, Frank. Tell me what you're trying to say.'

Frank brandished the pipe at me and closed his eyes while he formulated his response. It was probably a mannerism that dated all the way back to his time at Oxford. This chap Stinnes knows all about your wife's defection and subsequent employment and he interrogated you. Since that time there has been a departmental alert for him. When he's located in Mexico City why does Dicky Cruyer – the German Stations Controller, no less – go out there to look him over?'

'We both know the answer to that one, Frank. Dicky loves free trips to anywhere. And this one got him out of the way while Bret chiselled a piece out of Dicky's little empire.'

'Very well,' said Frank, in a way that made it clear that he didn't agree with my interpretation of those events. 'So why send you?'

'Because I work with Dicky. With both of us out of the way Bret had a better excuse for "taking over some of the workload".' I imitated Bret's voice.

'You're barking up the wrong tree,' said Frank. 'They want to enrol Stinnes. That was a decision of the steering committee, and it's been given urgent priority. They want Stinnes over here, spilling the beans to a debriefing panel.'

'About Fiona?'