'Of course you'd say that,' she said peevishly. 'It's your job to encourage us.'

'By the time Dr von Munte gets back here, it will be time to think about leaving.'

'Why do you make him come all the way back here before we leave? Why couldn't we meet him in town?'

'It's the way it's been planned,' I said.

She looked at me and shook her head. 'It's so that you can look at those papers he's bringing you. It's to give you a chance to cancel everything. Walter told me what you said.'

'Why not read your book?' I said. It was an anthology called More Short Stories from Poland. Twice or three times she'd started to read it and then put it down. Her mind was on other things. I said, 'There is nothing to be gained from letting these thoughts go round and round in your mind.'

'How do I know my husband isn't already on his way?'

'To the West?'

'Yes. How do I know he's not already on his way?'

'He wouldn't go anywhere without you, Frau von Munte.'

'Perhaps that disappointed you,' she said. There was a hard note of satisfaction in her voice. 'You wanted Walter to go on his own, didn't you?'

'No,' I said.

'Oh, yes, you did. You made the arrangements for just one person. You were going to leave me here.'

'Is that what Dr von Munte told you?'

'He confides in me. That is what our marriage has always been.'

'What else has he confided to you?' I asked. I smiled to soften my question.

'I know what he's gone back to his office for, if that's what you mean.'

Tell me, then.'

'A paper of some kind, handwritten by a communist agent. Someone very highly placed in the London intelligence service.'

I didn't deny that she was right.

'Yes,' she said. 'And you'll recognize the handwriting and you'll know who it is.'

'I hope so,' I said.

'But what will you do then, I wonder. Will you reveal who it is or will you use it for your own purposes?'

'Why do you say that?'

'It's obvious to me,' she said. 'If you wanted only to reveal the truth, you could have had the papers sent to London. But you want to look at them. You want to be the one who has the power.'

'Would you make some more coffee, please?'

'My husband is too nice,' she said. 'He'd never use the sort of power he has to advance himself. He does what he does because of his beliefs.' I nodded. She went to a tiny sink, which could be closed inside the cupboard when not in use, filled the electric kettle and switched it on. 'We bought this Laube during the war, Walter said the bombs were less dangerous in the soft earth. We grew potatoes, leeks and onions. There was no electricity then, of course, and we had to go a long walk to get drinking water.' She talked compulsively, her arms akimbo as she stared at the kettle. I noticed her small red hands and her red bony elbows as she rubbed her arms as if she felt cold. She had concealed her nervousness until now, but it is often accompanied by such bodily chills. She waited until the kettle came to the full boil before pouring the water into the pot. 'Do you have a wife?' she asked. She'd put a felt cover on the coffee pot and now she clasped it with her open hands to feel the warmth of it. 'Does she sit at home all day getting bored?'

'She goes to work,' I explained. 'She works with me.'

'Is that how you met? I met Walter at the big house his parents had near Bernau. They are an old important family, you know.'

'I met your husband's father once,' I said. 'He was a remarkable old man. I was only a small child, but he spoke to me as an equal. And a few days later, he sent me a leather-bound copy of Die schöne Müllerin. It had come from his library, and had his name embossed in gold on the cover and an engraved bookplate inside. My father told me that only a dozen books from his library had survived the war. I have it still.'

'You lived in Berlin as a child. That explains your perfect Berlin accent.' She seemed more relaxed now that she knew I'd met old von Munte. 'Hundreds of local people went to the old gentleman's funeral. They had it out there at the house where all the rest of the family had been buried. My father was a country physician. He attended the old man right until the end. What did your father do for a living?'

'He started out as a clerk. In the thirties he was unemployed for a long time. Then he went into the Army. The war began and he became an officer. After the war he stayed in the Army.'

'I'm Walter's second wife, of course. Ida was killed in one of the very first air raids.' She poured coffee for us. 'Do you have children?'

'Two: a boy and a girl.'

'It's Ida's child, of course – the one he wants to see.' She pushed the large cup of black coffee across the table to me in a gesture that contained an element of rejection.

'In São Paulo?'

'There's only the one child. That's why Walter dotes on him so much. I hope and pray he is not disappointed.'

'Disappointed how?'

'It's such a long time,' she said as if on that account the chances of the two men disappointing each other were self-evident.

'He's sure to be grateful,' I said. 'Walter has given him so much.'

'He's given his son everything,' she said. 'He's given him every penny he's earned from you. He's given him the life that was rightfully mine.' She drank some coffee. Her words were bitter but her face was calm.

'And now his son will be able to thank you both.'

'We'll be strangers to him. His son won't want the burden of looking after us. And Walter has no chance of earning any more.'

'It will be all right,' I promised vaguely.

'Our presence will remind him of his obligation, and he will resent that. Then he'll start feeling guilty about such feelings and associate us with that guilt.' She drank more coffee. She'd obviously been thinking about it a great deal. 'I'm always a pessimist. Is your wife a pessimist?'

'She had to be an optimist to marry me,' I said.

'You haven't told me how you met,' said Mrs Munte.

I mumbled something about meeting her at a party, and went over to look out the window. She'd arrived with two other girls. Dicky Cruyer knew her name, and so I immediately approached her with a bottle of Sancerre and two empty glasses. We'd danced to music from an old broken record player and discussed our host, a Foreign Office junior clerk who was celebrating a posting to Singapore.

Fiona was typing letters for a travel company in Oxford Street. It was a temporary job, due to finish the next week. She asked me if I knew of any really interesting work for someone with a good degree who could type and take shorthand in three languages. I didn't think she was serious at first. Her clothes and jewellery made her look anything but desperate for employment.

'She told me she was out of work,' I said.

At the time, Bret Rensselaer was setting up an undercover operation that worked out of an office block in Holborn and processed selected data from the Berlin office. We needed staff and Bret had already decided that we would not go through the normal civil-service recruitment procedure. It took too long and involved too much form-filling and interviewing; to make matters worse, the civil service only sent us applicants that the Foreign Office had already decided were not good enough for them.

'What was she wearing?' said Mrs Munte.

'Nothing special,' I said. It was a tight sweater of angora wool. I remember it because it took two dry cleanings and a lot of brushing to remove the final fluffs of wool from my only good suit. I asked her where she'd learned shorthand and typing and she cracked some silly joke that made it clear that she was an Oxford graduate, and I pretended not to understand such subtlety. Dicky Cruyer tried to cut in on our dancing at that point, but Fiona said couldn't he see that she was dancing with the most handsome man in the room?