She looked suddenly weary, saying nothing and stubbed out her cigarette, half smoked.

'You all right, Sal?' I said.

'I'm not sleeping well,' she said. 'Nobody's been in touch with you? Nothing suspicious?'

'I'll get in the car and drive home if you bring that up again. Don't be ridiculous. It's over.'

She paid no attention. 'You see, that was the mistake, my mistake. It's bothering me: you should have gone to meet him under a false name.'

'That wouldn't have worked. He'd have checked up on me. I had to tell him honestly who I was. We've had this conversation a hundred times. Please.'

We sat in silence for a while.

'Where's Jochen?' I said.

'Inside – drawing.'

'We should head off.' I stood up. 'I'll get his bits and pieces.' I folded away Rodrigo's letter and as I did so I thought about something.

'What I still don't understand,' I said, 'is why Romer would have become a Russian agent in the first place.'

'Why did any of them?' she said. 'Look at them: they were all middle-class, well educated, privileged, establishment figures.'

'But look at the life Romer was leading – everything about him, the way he lived. Money, position, power, influence, lovely houses. "Baron Mansfield of Hampton Cleeve" – he even had a title. The boy locked in the English establishment sweetshop, wouldn't you say?'

My mother had risen to her feet also and was now wandering about the back lawn, picking up Jochen's scattered toys. She stood up, a plastic sword in her hand.

'Romer used to say to me that there are only three reasons why someone will betray their country: money, blackmail and revenge.'

She handed me the sword and picked up a water pistol and a bow and two arrows.

'It wasn't money,' I said. 'It wasn't blackmail. So what revenge was he after?'

We walked back to the cottage together.

'In the end it comes down to a very English thing, I believe,' she said, seriously, thoughtfully. 'Remember, I didn't come here until I was twenty-eight. Sometimes, if you don't know a place, you can see things the locals miss. Remember, also, Romer was the first Englishman I really got to know… Got to know well,' she added, and I sensed the pain of her past still living, stirring beneath the recollection. She looked at me, with her clear-eyed look, as if daring me to refute what she was about to say next. 'And knowing Lucas Romer, as I did, and talking to him, being with him, watching him, it struck me that sometimes it's just as easy – and maybe sometimes more natural – to hate this country as to love it.' She smiled, knowingly, ruefully. 'When I saw him that night: Lucas Romer, Lord Mansfield with his Bentley, his butler, his Knightsbridge house, his club, his connections, his reputation…' She looked at me. 'I thought to myself: that was his revenge. He'd got it all: everything that seems most desirable – money, reputation, esteem, style, class – the title. He was a "Lord", for God's sake. He was laughing all the time. All the time, laughing at them all. Every minute of the day, as his chauffeur drove him to his club, as he went to the House of Lords, as he sat in his Knightsbridge drawing-room – he was laughing.'

She made a resigned face. 'That's why I knew – absolutely, without question – that he'd kill himself that night. Better to die acclaimed, fondly remembered, admired, respected. If there was a heaven he'd still be laughing, looking down at his memorial service with all those politicians and dignitaries celebrating him. Dear old Lucas, fine fellow, salt of the earth, a true-blue English gentleman. You say I won – Romer won, too.'

'Until Rodrigo publishes his book. It's going to blow everything wide open.'

'We must have a talk about that one day soon,' she said, severely. 'I'm not all that happy about it, to tell you the truth.'

We found Jochen; he gave her his drawing – of a hotel, he said, nicer than the Ritz – and we packed everything away in the car.

'Oh, yes,' I said, 'one thing that's been on my mind, I keep thinking about. It seems silly, but – what was he like, my uncle Kolia?'

She straightened up. 'Uncle Kolia,' she repeated, as if testing the phrase, savouring its unfamiliarity. Then I saw her eyes narrow, keeping the tears back. 'He was rather wonderful,' she said with false briskness, 'you would have liked him.'

I wondered if I had made a mistake, recalling him to her like that, at this particular moment, but I had been genuinely curious. I fussed Jochen into the car and settled myself inside.

I wound down the window, wanting to reassure her, one last time.

'Everything's fine, Sal. It's over, finished. You've no need to worry anymore.'

She blew us a kiss and wandered back inside.

We had just driven out of the gate when Jochen said, 'I think I left my jersey in the kitchen.' I stopped the car and climbed out. I went back in through the front door, pushing it open and calling cheerily, 'It's just me,' and walked through to the kitchen. Jochen's sweater was on the floor under a chair. I stooped and picked it up and realised my mother must have gone back out to the garden.

I peered through the window, looking for her, and saw her, eventually, half hidden by the big laburnum by the gate in the hedge that gave on to the meadow. She was looking through her binoculars, trained on the wood, traversing slowly this way and that. Across the meadow the big oaks still heaved and thrashed in the wind and my mother searched amongst their trunks, amongst the darkness of the undergrowth, for signs of someone watching for her, waiting to find her unguarded, at ease, uncaring. It was then that I realised this was exactly how she never would be. My mother would always be looking towards Witch Wood, as she was now, waiting and expecting that someone was going to come and take her away. I stood there in the kitchen, watching her staring across the meadow still searching for her nemesis and I thought, suddenly, that this is all our lives – this is the one fact that applies to us all, that makes us what we are, our common mortality, our common humanity. One day someone is going to come and take us away: you don't need to have been a spy, I thought, to feel like this. My mother watched on, staring across the meadow at the trees.

And the trees in the dark wood moved and shifted in the wind, and the sun patches skidded across the meadow, cloud shadows rushing by. I saw the blond uncut grass bend and flow almost like a living thing, like the pelt or fleece of some great animal: wind-combed, wind-stirred, ever-moving – and my mother watching, waiting.

William Boyd was born in Ghana. He was brought up there and in Nigeria. He was educated at the universities of Nice, Glasgow and Oxford. He is married and lives in Chelsea, London.

He is the author of eight previous novels. A Good Man in Africa won the Whitbread Literary Award for the Best First Novel; An Ice-Cream War won the John Llewellyn Rhys Memorial Prize and was shortlisted for the Booker Prize; Brazzaville Beach won the James Tait Black Memorial Prize and The Blue Afternoon was the winner of the Los Angeles Times Book Prize for Fiction.

His most recent novel was Any Human Heart.

In addition, some thirteen of his screenplays (including the adaption of his novel Armadillo) have been filmed and in 1998 he both wrote and directed the feature film The Trench.