She kissed his cheek. 'Harry. We are happy enough this way. And we have lots of time.' It was the same conversation they'd had many times before.

'Not if we were to start a family. Not much time.'

'Is that what you want?'

'You know it is. Our children, Fiona. It's everything I want.'

'You'd come and live here?' She was testing him now.

'I lived here before.'

'That's not the same thing as living here permanently,' she said.

'Do I hear a discordant note in the Marxist harmony?'

'I'm stating a fact.'

'You don't have to be defensive, honey.'

'You said you were a Marxist,' she reminded him. It was unfair to remind him of something he'd said only once, and that in a heated argument.

'Yes. I said I was a Marxist. I was a Marxist a long time ago.' The sail began drumming.

'But no longer?'

He pulled the mainsheet to adjust the sail before turning his head to answer. He was a good sailor, quick and expert in handling the boat and everything else he did. 'I asked myself a question,' he said.

'And?'

'That's all. Marxism is not a creed for those who question.'

'No matter what the answer? Is that true?'

'Yes. Whatever the answer: one question gives birth to another. A thousand questions follow. Nothing can sustain a thousand questions.'

'Nothing? Not even love?'

'Don't mock me.' They were near the shore now: all forest, no sign of people anywhere. 'Ready about!' said Harry in the flat voice he used when commanding the boat.

Stepping carefully she went forward, released the front sail and watched him as he swung the tiller. The boom crashed across the boat as they passed through the wind and instinctively he ducked his head to avoid it. She pulled in the jib and set the front sail before going back to sit down.

'Do you ever play let's pretend?' he said as he settled back on the seat. It was another aspect of his childishness. Flying planes was childish too: perhaps he'd joined the Communist Party as some silly adventure.

'No,' she said.

'I do. Sitting here, just the two of us in the boat, cruising across the Muggelsee, I pretend that you are an alluring Mata Hari and that I am the heroic young fellow in your spell who has come to rescue you.'

She said nothing. She didn't like the drift of this conversation but it was better to see what came of it.

'Pursued by black-hearted villains, the other shore is safety: a place where we'll live happily ever after, and raise our family.'

'Sounds like A Farewell to Arms,' said Fiona without putting too much enthusiasm into the idea. 'Did you ever read that?'

'The journey across the lake to Switzerland. Hemingway. Yes, I did it for my high school English. Perhaps that was where I got it.'

'The woman dies,' said Fiona. They get to Switzerland but the woman dies in hospital.' She turned to look at him and he seemed so utterly miserable that she almost laughed.

'Don't make jokes,' he said. 'Everything is perfect.' She hugged him in reassurance.

Yes, everything had been perfect for Harry. It was easy for him. But Fiona was coming near to the end of her resources. She was desperately depressed, even out here on the lake with a man who loved her. Depression, she'd found, was no respecter of logical truth; it was some dark chemical cloud that descended upon her at random and reduced her to jelly.

It was no good telling herself that it was nonsense. She'd given up her children and her marriage. Was she being paranoid to think that Bernard would have completely poisoned the children's minds against her by now? She had run away, why wouldn't they be hurt by such rejection? How could she hope to become wife and mother again?

The children were the most terrible sacrifice she had made, but there were other wounds too. She had lost friends and family who now despised her as a traitor. And what was it all for? She had no way to judge the results, or the contribution she'd made. She'd begun to suspect that she was the lamb slaughtered at the altar of Bret Rensselaer's ambition. Bret's wounds were corporeal: his reputation intact. Bret Rensselaer was the winner. So were Silas and the D-G. Three old men had sent her here: and those three would be the victors. What did they care about her? She was expendable: as useful and as readily discarded as a Kleenex tissue.

Fiona was the loser: Fiona, her husband and her children. They would never recover from what she had done. Was any political – or as Bret so liked to have it: economic – victory worth it? The answer was no.

Sometimes she felt like salvaging what little she had left. She felt like grabbing a chance of happiness with Harry, of severing her contact with London and just settling down in East Berlin as a Hausfrau. But that would be no more than a temporary salve. The real loss was Bernard and the children: she wanted them to love her and need her.

'A penny for them?' said Harry.

'I was thinking about my hair,' she said. 'About having it cut shorter.' Men were always ready to believe that women were thinking about their hair.

He smiled and nodded. She was looking much older lately: they both were. A vacation in the Danube Delta would be good for both of them.

That evening she had a meeting with Werner Volkmann. She waited there alone in her old-fashioned apartment looking out over the Frankfurter Alice, the wide main road that led eventually to Moscow and, perhaps for that reason, was once called Stalin Alice. It was a part of the procedure that agents running back and forth did not come up to the office. They met privately. She looked at her watch: Werner was late.

She tried to read but was too jittery to concentrate. She found herself trying not to look at Pariser Platz, which was hanging over her bed. It was in a neat black ebony frame. One evening she had taken it down and opened the frame in order to replace Kirchner's kitsch gaiety with an abstract print more to her taste. Behind the street scene she had been horrified to come across a coloured print of Lochner's The Last Judgment. As such medieval paintings go, it was a mild example of the violent horrors waiting for sinners in the next world, but Fiona, alone and tired and troubled, had been thunderstruck by the demented and distorted figures and terrifying demons. It was as if she was meant to find it lurking under the cosiness of the Berlin street scene. With trembling hands she'd replaced The Last Judgment back under the Kirchner and fixed it into its frame, but from that time onwards she was never unaware of the presence of that tormented world that lurked under the frolicsome Pariser Platz.

Werner apologized for being late. He was rainswept and weary. He said it was the strain of winding down his banking business and trying to run Lisl Hennig's hotel at the same time, but Fiona wondered if it was the stress of being a double agent. Werner was a West German national. If the security services became convinced that he was betraying them he would simply disappear without trace or, worse still, become a patient in the Pankow clinic.

They chatted for ten minutes, the sort of unimportant talk they might have had if Werner was what he purported to be. Only then did Fiona disconnect the voice-actuated microphone which she had discovered on the first day she got here. Senior staff had their conversations recorded only by random checks, but it was better to be safe.

'Did you see the children?' Before answering he went and sat in the only comfortable chair with his overcoat still on. He wasn't feeling cold: Werner often kept his overcoat on. It was as if he wanted to be ready to leave at short notice. He'd even kept hold of his hat, and now he was fidgeting with it, holding it in both hands like the steering wheel of a heavy truck that he was negotiating along a busy road.