'Okay, Frank,' I said. 'Strictly need to know, from now onwards and for ever more.'

'That's a sensible fellow,' said Frank. 'Think of the children, Bernard. They rely on you now that Fiona's gone.'

'I know they do, Frank.'

I hadn't promised Frank Harrington anything I hadn't already promised myself. It seemed as if everyone in the Western world was keen to tell me that Bret Rensselaer was clean-cut, upright and true, It would have been stupid in the light of so many reassurances to continue poking and probing into the work he was doing before my wife Fiona defected.

That afternoon I went back to work with renewed vigour. By Thursday my desk – despite a second onslaught from Dicky's out-tray – was virtually clear. To celebrate my new freedom from extra-curricular detective work I took Gloria and the children for a weekend in the country. It was the new girl's first weekend off, having worked for us for no less than six days. We started early Saturday morning. In a ten-acre field near Bath we visited a 'Steam Engine Rally', a collection of ancient steam-powered machines: harvesters, roundabouts, tractors and rollers. All working. The children adored every moment of it. Gloria seemed to become even younger and more beautiful. Despite the constant presence of the children she kept saying how wonderful it was to have me to herself. I think it was the first time that all four of us discovered that we were a family, a happy family. Even twelve-year-old Sally, who'd hitherto shown a certain reserve about Gloria, now embraced her in a way I'd almost stopped hoping for. Billy – usually so prosaic and self-contained – took Gloria for a walk and told her the story of his life, and gave her a few hints and tips on handling the new girl's 'ratty' moods, which seemed to be frequent and varied. I was not optimistic about the girl. Doris, I now realized, wasn't so bad after all.

On Saturday evening we found Everton, a pretty little village. We had dinner in the hotel. It was a long drive back to London, so on impulse we stayed there overnight. Gloria with feminine foresight had put some overnight things, including the children's toothbrushes and pyjamas – and even the spare elastic bands Billy had to put on his wired teeth – into a bag in the back of the car. I remembered that weekend for ever afterwards. Gloria's future education was not discussed. On Sunday morning we all went for a walk across the fields without seeing another soul. We followed a stream that was filled with fish and ended up in a tiny riverside pub decorated with photos, theatre programmes, playbills and other mementoes of Maria Callas. We drank a bottle of Pol Roger. Billy got very muddy and Sally picked flowers. Gloria told me that it could be like this for ever and ever, and I allowed myself to believe her.

The children were growing up so fast that I could hardly reconcile this tall young fellow walking alongside me with the child that Billy had been only a few months ago. 'Girls don't understand about moving,' he said, as if continuing a conversation we'd already started, although in fact we'd been giving all our attention to the prospect of scrambling across a stream.

'Sally you mean?'

'Yes, she had these special friends at her school in Marylebone.'

'More special than your friends?' I said.

'It's all right now. She likes it at the new place. Girls only want to talk about clothes,' said Billy, 'so it hardly matters where she is.'

'And what about you?'

I'm going to join the Vintage Car Club.'

I concealed my surprise. 'Are you old enough? Don't you have to have a car?'

'They will probably let me help… fixing the engines and pumping up the tyres.' He looked at me. 'I like our new house, Dad. So does Sally. So don't worry about us.'

'I'll go first,' I said and I took his arm and swung him across the water. He was heavy, damned heavy. I would never carry him on my shoulder again.

Now it was Billy's turn to extend a hand to me. And when I'd negotiated the steep muddy bank he said, 'I saw Grandpa the other day.'

'Grandpa?'

'He's got a new car, a Bentley turbo, dark blue. He came to the school.'

'You spoke to him?'

'He drove us home.'

'I thought nanny met you.'

'She came too.'

'I should have taken you to see him,' I said.

'He said we could have a holiday with him. He's going to Turkey. He might drive there: drive all the way.'

'Grandpa? You're not making this up, Billy?'

'Could we go. Daddy? Perhaps in the Bentley.'

'Did you tell Auntie Gloria about this?'

Billy looked contrite. He stared down at his muddy shoes and spoke quietly. 'She said I wasn't to tell you. She said you'd worry.'

'No, it's all right, Billy. I'll have to see about it. Maybe I'll talk to Grandpa.'

'Thank you, Daddy. Thank you, thank you!' Billy hugged me and said, 'Do you think Grandpa would let me sit up front?'

'Turkey is a long way away,' I said.

'There's Sally and Auntie Gloria,' he shouted. 'They must have found a way across the stream.'

So it had started. If it was simply a matter of going on holiday, why hadn't Fiona's father come to me and asked? Turkey: the USSR just a stone's throw away. The idea of my children being there with my meddlesome father-in-law filled me with dread.

Billy's little story cast a grey shadow across our idyll, but it was that bloody old fool Dodo who caused all the trouble to start again for me. At our first meeting in France I'd seen him as an amiable eccentric, a cultured old man who occasionally took too much to drink. Now I was to encounter the malicious, self-aggrandizing belligerent old drunk that was really him.

Although it was never confirmed, I have no doubt that Gloria's mother had spoken on the phone with him and poured her heart out about being neglected and lonely. Gloria said that in some unspecified time in the distant past the old man had always been fond of her mother. Dodo however told everyone he met in London that he was 'on business'. Whatever the reason, Dodo suddenly appeared in London, dressed up in an old but beautifully cut Glen Urquhart suit, and for the first week he was staying in the Ritz; a room with a view across the park.

He had contacts of course. Not only expatriate Hungarians and the people he'd known during his time in Vienna, but 'departmental' people too. For Dodo had been one of Lange's 'Prussians' and for some people that was commendation beyond compare. He'd also played some unrevealed part in the Budapest network of which Gloria's father had been a member before escaping across the border. And Dodo was a man who could be relied upon to keep in touch, so 'old pals' from the Treasury and the Foreign Office took Dodo to lunch at the Reform and the Travellers.

He liked to go to parties. He went to embassy parties, show-biz parties, 'society' parties and literary parties. How much time he spent with Gloria's parents, and whether they talked about me, and speculated upon the work I did, was never established. But by the time I encountered him again, Dodo was disturbingly well informed about me.

Dodo's invitation to have drinks with 'friends of mine – Thursday 6-8pm or as long as people stay…'at a smart address in Chapel Street near Eaton Square was scribbled on Ritz notepaper and arrived in the post on Wednesday morning. It was not adequate preparation for what we met there. We arrived at a small town house typical of London South West One. Outside in the street there were expensive motorcars, and a formally dressed butler opened the door. Many of the guests were in evening clothes and the women in long dresses. There was the sound of live music and loud laughter. Gloria cursed under her breath, for she was wearing a tweed suit that had been relegated to her working day, and she'd not had time to fix her hair.