'I miss Mummy,' said Sally. 'I wonder why she didn't visit us for Christmas.'

'Gloria is nice,' said Billy, who had rather fallen for her. 'What is separated?' He had heard that his parents were separated but he was not sure exactly what this meant.

Sally said, 'Nanny said Mummy and Daddy have to live in different countries so that they can find themselves.'

'Can't they find themselves?' said Billy. He chuckled, 'It must be terrible if you can't find yourself.'

Sally didn't find this funny at all. 'When she finds herself Mummy will come back.'

'Does it take long?'

'I'll ask Nanny,' said Sally, who was clever at wheedling things out of the quiet girl from Devon.

'Is Daddy finding himself too?' And then, before Sally could reply, he found a piece of sky and fitted it into the puzzle.

'I saw that bit first,' said Sally.

'No you didn't! No you didn't!'

Sally said, 'Perhaps Daddy could marry Mummy and marry Gloria too.'

'No,' said Billy authoritatively. 'A man can't have two wives.'

Sally looked at him with admiration. Billy always knew everything. But there was a look she recognized in his face. 'Are you all right?' she said fearfully.

'I think I'm going to be sick,' said Billy.

East Berlin. February 1984.

Hubert Renn seldom voiced his innermost thoughts, but had he done so in respect of working for Fiona Samson, he would have said that the relationship had proved far better than he'd dared hope. And when, in the first week of January 1984, he was offered a chance to change jobs and work at the Normannenstrasse Stasi headquarters, Renn declined and went to considerable trouble to provide reasons why not.

Hubert Renn preferred the atmosphere of the small KGB/Stasi command unit on Karl Liebknecht Strasse. And, like many of the administrative staff, he enjoyed the feeling of importance and the day-to-day urgency that 'operational' work bestowed. Also he'd adopted a paternal responsibility for Fiona Samson without it ever becoming evident from the stern and formal way in which he insisted that the office must be run. Neither did Fiona Samson ever demand, or seemingly expect, anything other than Renn's total dedication to his work.

Renn did not find it difficult to understand Fiona Samson, or at least to come to terms with her. This mutual understanding was helped by the way in which Fiona had suppressed and reformed her femininity. The uncertainties and the misgivings that child-bearing and marriage had given her no longer influenced her thoughts. She was not masculine – men and their reasonings were no less puzzling now than they'd ever been – but she was simplistic and determined in the way that men are. Even at her most feminine, she had never fallen into the role of victim the way she'd watched her mother and her sister and countless other women readily play that part. Nowadays, whenever something came up that she was unable to deal with on her own terms, she asked herself what Bernard would do in the same situation, and that often helped her to solve the problem. And solve it without delay.

Had she been perfectly fit, things would have been entirely endurable. But Berlin had got to her. For Bernard it was a second home and he loved it but for Fiona it was a city of bad dreams. She had come to the conclusion that her bouts of depression and the nightmares from which she so often awoke sweating and trembling were not solely brought on by loneliness, or even by the guilt she felt at having abandoned her husband and children. Berlin was the villain. Berlin was eating her heart away so that she would not ever recover. It was nonsense of course, but she was becoming unbalanced and she was aware of it.

In the privacy of her Frankfurter Alice apartment, when she was not slaving over work or trying to improve her German and her Russian, she did sometimes find time to reflect upon the reasons why she found herself in this desperate situation. She dismissed the narrative analysis, the sort of reasoning beloved of psychologists and novelists, that would undoubtedly draw a straight cause-and-effect line through her authoritarian father, the boarding school, her secret government work and its apotheosis in this assumption of another life. It hadn't happened like that. The ability to play out this role was something she'd worked hard to perfect: that part of her illness wasn't a manifestation of some flaw in her personality.

She'd liberated herself from being that little girl who'd gone to boarding school shivering with apprehension, not by marching or shouting slogans but by stealth. That was why the transformation was so complete. She had actually become another person! Although she would never admit it to a living soul, she had even given a name to this tough employee who came to work in the Karl Liebknecht Strasse every day, and slaved hard for the German socialist state: the person was Stefan Mittelberg – a name she'd compiled when perusing a directory – a man's name of course, for in the office she had to be a man. 'Come along, Stefan,' she'd tell herself each morning, 'it's time to get out of bed.' And when she was brushing her hair in front of the mirror, as she always did at the start of each day, she would see hard-eyed Stefan looking back at her. Was 'Stefan' a manifestation of emotional change? Of hardening? Of liberation? Or was 'Stefan' the one who'd had the spontaneous love affair with Harry Kennedy? How else would one explain an act so totally out of character? Well, 'Stefan' was a success story; the trouble was, she loathed 'Stefan'. No matter, perhaps in time she would learn to love this new tougher self.

In the office she concentrated upon becoming the perfect apparatchik, the sort of boss that a man such as Renn would want to work for. But she was a foreigner and she was a woman, and sometimes she needed help and advice when dealing with the devious intrigues of the office.

'How long will the new man be working here?' Fiona asked Renn one day when they were tidying away boxes of papers and celebrating a completely clear desk.

Renn looked at her, amazed that she could be so innocent and ill-informed. Especially since Fiona's Russian award had now come through. She'd been given it at a little ceremony in the hall at Normannenstrasse. Renn had enjoyed a share of the glory. 'New man?' he said. He never rushed into such conversations.

The young one… yellow wavy hair…'She paused. 'What have I said?'

Renn found her ignorance both appalling and endearing. Everyone else in the building had learned how to recognize an officer of the political security service in Moscow. 'Lieutenant Bakushin, do you mean?' he asked her.

'Yes. What is he here for?'

'He was one of the executive officers on the Moskvin inquiry.'

'Moskvin inquiry? Pavel Moskvin?'

'But yes. It was held in Moscow last week.'

'Inquiry into what?'

'Conduct.'

'Conduct?'

'That is the usual style. Such inquiries are secret, of course.'

'And is the verdict announced or is that secret too?'

'Lieutenant Bakushin is collecting further evidence. He will probably want to talk to you, Frau Direktor.'

'But Moskvin has just been promoted to Colonel,' said Fiona. She still didn't understand what Renn was trying to tell her.

'That was simply to make it easier for him to give instructions to the Embassy people while he is in London. Here rank does not count for as much as it does in the West. It is a man's appointment that decides his authority.'

'And Lieutenant Bakushin's appointment is a high one?'

'Lieutenant Bakushin could arrest and imprison anyone in the building, without reference to Moscow,' said Renn simply. It made Fiona's blood run cold.

'Have you any idea what Colonel Moskvin was accused of?'