'That would be absurd, Bernard. You'll have only your salary in future. You won't have Fiona's trust fund, the children's trust funds or Fiona's salary.'

'The trust funds were used solely for Fiona and the children,' I pointed out to him.

'Of course, of course,' said David. 'But the fact remains that your household will have far less money. And certainly not enough to keep up a rather smart little house in the West End,'

'If I moved into a service flat there would be no room for the children.'

'I was coming to that, Bernard. The children – and I think you will agree unreservedly about this – are the most important single factor in this whole tragic business.'

'Yes,' I said.

He looked at me. 'I think I'll have a drink myself,' he said. He got up and went to the cupboard and poured himself a gin and tonic with plenty of tonic. 'And let me do something about yours too, Bernard.' He took my glass and refilled it. After he'd sipped his drink he started again but this time from another angle. 'I'm a socialist, Bernard. You know that; I've never made a secret of it. My father worked hard all his life and died at his work-bench. Died at his workbench. That is something I can't forget.'

I nodded. I'd heard it all before. But I knew that the work-bench was to David's father what David's easel was to him. David's father had owned half of a factory that employed 500 people.

'But I've never had any dealings with communists, Bernard. And when I heard that Fiona had been working for the Russians all these years I said to my wife, she's no daughter of ours. I said it just like that. I said she's no daughter of ours, and I meant it. The next morning I sent for my lawyer and I disowned her. I wrote and told her so; I suppose the lawyers handling her trust fund have some sort of forwarding address…' He looked at me.

'I don't know,' I said. 'I haven't contacted them. I daresay the department has contacted them but I don't know anything about a forwarding address.'

'Whether she'll ever get my letter or not I don't know.' He came over to where I was sitting and, lowering his voice, he added in a voice throbbing with emotion, 'And personally, Bernard, I don't care. She's no daughter of mine. Not after this.'

'I think you were going to say something about the children,' I prompted him.

'Yes, I was. Fiona has gone for good, Bernard. She's never coming back. If you're holding on to the house in the hope that Fiona comes back to you, forget it.'

'If she came back,' I said, 'she'd face a very long term in prison.'

'Yes, I thought of that,' he said. 'Damn it, that would be the final disgrace. Her mother would die of shame, Bernard. Thank God the story was never picked up by the newspapers. As it is I've cut back on visits to my clubs, in case I see someone who's in the know about such things. I miss a lot of my social life. I haven't had a round of golf since the news reached us.'

'It hasn't exactly made life easy for me,' I said.

'In the department? I suppose they think you should have got on to her earlier, eh?'

'Yes, they do.'

'But you were the one who finally worked out what was going on. You were the one who discovered she was the spy, eh?'

I didn't answer.

'You needn't worry, Bernard. I don't hold that against you. Someone had to do it. You just did your duty.' He drank some of his drink and gave a grim, manly smile. I suppose he thought he was being magnanimous. 'But now we have to face the mess that she's left behind her. My wife and I have discussed the whole thing at great length…' A smile to share with me the difficulties that always come from discussions with women. '… and we'd like to have the children. The nanny could come too so we'd preserve the essential continuity. I've spoken to a friend of mine about the schools. Billy has to change his school this year anyway… '

'I'm keeping the children with me,' I said.

'I know how you feel, Bernard,' he said. 'But in practical terms it's not possible. You can't afford to keep up the mortgage payments on the house the way the interests rates are going. How would you be able to pay the nanny? And yet how could you possibly manage without her?'

'The children are with my mother at present,'

'I know. But she's too old to deal with young children. And her house is too small; there's only that little garden.'

'I didn't know you'd been there,' I said.

'When I heard you were away in Mexico I made it my business to see the children and make sure they were comfortable. I took some toys for them and gave your mother some cash for clothes and so on.'

'That was none of your business,' I said.

'They're my grandchildren,' he said. 'Grandparents have rights too, you know.' He said it gently. He didn't want to argue; he wanted to get his way about the custody of the children.

'The children will stay with me,' I said.

'Suppose Fiona sends more Russians and tries to kidnap them?'

'They have a twenty-four-hour armed guard,' I said.

'For how much longer? Your people can't provide a free armed guard for ever, can they?'

He was right. The guards were still there only because I'd had to go to Mexico. As soon as I got back to the office there would be pressure to withdraw that expensive facility. 'We'll see,' I said.

'I won't see the children's trust funds squandered on it. My lawyer is a trustee for both the children; perhaps you're overlooking that. I'll make sure you don't use that money for security guards or even for the nanny's wages. It wouldn't be fair to the children; not when we can offer them a better life here in the country with the horses and farm animals. And do it without taking their money.'

I didn't answer. In a way he was right. This rural environment was better than anything I could offer them. But the bad news would be having the children grow up with a man like David Kimber-Hutchinson, who hadn't exactly made a big success of bringing up Fiona.

'Think it over,' he said. 'Don't say no. I don't want to find myself fighting for custody of the children through the law courts. I pay far too much money to lawyers anyway.'

'You'd be wasting your money,' I said. 'In such circumstances a court would always give me custody.'

'Don't be so sure,' he said. 'Things have changed a lot in the last few years. I'm advised that my chances of legal custody are good. The trouble is – and I'm going to be absolutely frank with you about this – that I don't fancy paying lawyers a lot of money to tell the world what a bad son-in-law I have.'

'So leave us alone,' I said. I'd feared I was heading into a confrontation like this right from the moment I saw the cream-coloured envelope in front of the clock.

'But I wouldn't be the only loser,' he continued relentlessly. 'Think what your employers would say to having your name, and my daughter's name, dragged through the courts. They wouldn't keep that out of the newspapers in the way they've so far been able to do with Fiona's defection.'

He was right, of course. His legal advisers had earned their fees. The department would keep this out of the courts at all costs. I'd get no support from them if I tried to hang on to my children. On the contrary; they'd press me to accept my father-in-law's sensible offer of help.

Beyond him, through the big studio windows, I could see the trees made gold by the evening sunlight and the paddock where Billy and Sally liked to explore. Money isn't everything, but for people such as him it seemed as if it could buy everything, 'I'd better be getting along,' I said. 'I didn't get much sleep on the plane and there'll be a lot of work waiting for me on my desk tomorrow morning.'

He put his hand on my shoulder. 'Think about it, Bernard. Give it a couple of weeks. Take a look at some of the bills coming in and jot down a few figures. Look at your net annual income and compare it with your expenditure last year. Even if you pare your expenses right down you still won't have enough money. Work it out for yourself and you'll see that what I've said makes sense.'