'Very well,' said Silas without turning to see him.

The man looked at him as if expecting some more earnest response. 'We'll go ahead then.'

'I said yes,' said Silas irritably.

The man looked at the back of Silas' head, looked at me, rolled his eyes and then withdrew. I waited to see if Silas would account for the interruption but he just said, 'I've rediscovered Wagner in my old age.'

'That's gratifying.'

After a long pause he said, I'm losing the elms. They've got that damned disease.'

'All of them?'

'The ones at the front.' He bit his lip. They've always been here: my father loved them. I suppose I shouldn't let myself become upset about those stupid trees but…'

'You can put in others,' I said.

'Yes, I'm going to put in six oaks.' He smiled. It was understandable that he identified so closely with the trees that had always framed the house from the drive. There would be more trees, and more people too, but Silas Gaunt would have been felled, fired and forgotten by the time they matured. He brought out a bright red cotton handkerchief, dabbed his eyes and blew his nose. 'Is it too smoky for you? Open the window if it is.'

I'm fine.'

'Fledermaus went well? You saw Fiona?' Outside there came the sound of the chainsaw being started up. His face stiffened but he pretended not to hear it.

'I saw her,' I said.

'It's clear to you now?'

It was still far from clear but there was little or nothing to be gained from saying so. 'So we're pulling her out?' I said, wanting him to confirm it.

'In due time.'

'It's a miracle she's lasted so long.'

'She's a damned good girl,' said Silas. 'A wonderful woman.'

'And Erich Stinnes is coming too?'

Silas looked at me blankly. He must have been momentarily diverted by the racket of the chainsaw. The sound of it came in longer and longer bursts as they severed larger and larger branches prior to the felling. A tree is like a network of course, and that's how the old wartime training manuals always depicted it. And like a tree, a network is destroyed beginning with a twig. Then a small branch, until it's uprooted and eradicated. 'Stinnes…' said Silas. 'Yes, I suppose so. Does Stinnes matter?'

'Matter?' I said. I was as puzzled as he seemed to be.

'Enrolling Stinnes… getting him to go back there and work for us was brilliant. It was the master touch,' said Silas. His eyes were bright and alert now. 'If Stinnes eventually comes back intact the Department will break every rule in the book to get a K for Bret Rensselaer.'

I looked at him carefully. So Stinnes was working for us. But surely what he really meant was if Fiona eventually comes back intact, but he didn't want to be that candid with me. 'Was that Bret's doing?'

'No. But sending Stinnes back was originally Bret's idea. Bret pushed and pushed for it.'

'It was madness,' I said. 'Maybe Stinnes pulled it off; maybe they are playing with him. Who can be sure? Either way sending him back was reckless. It endangered Fiona.'

'Can't you see it, even now?' said Silas. He shook his head at my slowness. 'We didn't care a jot what happened to Erich Stinnes, and we still don't. Stinnes was sent back there for one reason, and for one reason only: to reinforce the story that Fiona was a genuine defector.'

'Not to work alongside Fiona?'

'No, no, no. That was the beauty of it. No one revealed to Stinnes that Fiona went back to work for us; because virtually no one there knows. Every one of our people believes that Fiona's defection was the worst blow the Department ever suffered, and whatever suspicions passed through his mind Stinnes went back believing that too.'

I said, 'Do you mean Stinnes was told to report and defuse what Fiona was supposedly doing to us?' It was beautiful. It had the symmetry that distinguishes art from nature.

Silas smiled contentedly as he watched me thinking about it. 'Yes, "Operation Damage Control", that's what Bret told Stinnes he was. Stinnes was just a means to an end.'

'And so was I,' I said bitterly. 'I've been made a fool of, right from the start.' The revelation that my wife was a heroine, rather than a traitor, should have made me rejoice. In some ways it did, but on a personal level I felt bitter at the way I'd been used. My anger extended to everyone who knew about Fiona's long-term commitment, and had kept it from me. Everyone included Fiona. From outside, the sound of the chainsaw was now continuous. They must have been cutting through the trunk.

'You mustn't look at it like that,' said Silas. He sighed. It wasn't one of the histrionic sighs he'd used in the old days. It was the sigh of a sick old man who finds the effort of living too much for him. 'You played a vital role in what happened. What sense was there in having you worry about the operational side?'

'That's what Fiona said. Was this what you wanted to see me about?' I asked.

'That damned quack says I could go any time.'

I nodded. He looked ill. Mrs Porter wasn't worrying unnecessarily.

'I suppose Mrs Porter told you that. She tells everyone. I can see from the look in their faces when they come in here to talk to me.'

'She's very discreet,' I said to calm his anger.

'What will happen when I go, I've been asking myself. Bret is sick, and anyway Bret doesn't know the whole story. The D-G knows but no one will listen to him because they say he's batty. What do you think about him?'

These were dangerous waters and I navigated away. 'I haven't seen him for a long time,' I said.

The rumour is that he has Alzheimer's, but my quack says the only way they can confirm Alzheimer's is by means of a post-mortem.' There was a sudden silence and then a soft thud and a muddle of voices as the felled tree hit the wet lawn. The sound of its death saddened me. Silas gave no sign of having heard it but I knew he had. 'Do you know what I think?' He shifted restlessly. A man as big and powerful as Silas was apt to resent infirmity in a way that other men did not. He eyed me to make sure I was giving him my full attention. Then he said, The old man's deaf.'

'Yes,' I said. 'Everyone knows that.'

'Even more deaf than he admits,' said Silas. They all think he's crazy because he's too damned vain to get himself a modern hearing aid. I think the D-G is as smart as you and I.'

'I'd like to think you are right,' I said, and then tried to get back to the point. 'So you, Bret and the D-G are the only ones who know that Fiona is one of ours?'

'That's exactly right. Even the Vienna team who arranged the meeting for you last week think she was acting for Moscow.'

I'm relieved to hear it.'

'If all three of us – me, Bret and the D-G – go at once, and that's not beyond the bounds of credibility, you and Fiona will be the only ones who know the true story. Even the case officer processing her report is not really a case officer; he doesn't know where they come from.'

'And so I'd have little chance of convincing anyone that she's one of ours.'

'And Fiona won't dare try.' He gave a little cough to clear his throat. 'Yes, that's the position, Bernard. That's why I sent for you.'

'What do you propose we do?' I said.

'Wait.' I looked at him. His face was white and bloated but ill or not, it still displayed the fierce determination that he'd always shown. 'We can't pull Fiona out until the time is right.'

'Don't wait too long, Silas,' I said. 'Agents get over-confident, we both know that. She'll have to be ordered out. I wanted her to come back with me.'

'And undo everything she's worked for? Bernard your wife is a perfectionist. Surely you must have realized that during your married life with her?'

'No,' I said. All I'd discovered during my married life with Fiona was that, although I'd shared with her just about every idea, thought and emotion I had, she'd guarded her own secrets with a discipline that was no less than obsessional. I felt as if I'd been swindled. Not bilked, burned or ripped off for a short-term loss but systematically deceived for years and years by the person who had vowed to love me and care for me. Fiona Kimber-Hutchinson, do you take this bachelor? Yes, I was taken.