I collected the drinks and made my way back towards her table.

‘Thanks,’ she said, taking the glass from me and throwing its contents down her throat in one go.

‘Steady,’ I said.

She looked at me for a moment with real aggression, as if I was just one more person at the end of a long line, getting in her way, telling her what to do. And then she remembered who I was - or remembered to pretend to remember who I was - and smiled. I smiled back.

‘Twelve years ageing in a sherry cask,’ I said cheerfully, ‘stuck out on aHighland hillside, waiting for its big moment ‘- and then bang, doesn’t even get to touch the sides. Who’d be a single malt whisky?’

I was wittering, obviously. But under the circumstances, I felt entitled to do a bit of that. I had been shot, beaten, knocked off my bike, imprisoned, lied to, threatened, slept with, patronised, and made to shoot at people I’d never met. I had risked my life for months, and was hours away from having to risk it again, along with a lot of other lives, some of which belonged to people I quite liked.

And the reason for it all - the prize at the end of this Japanese quiz show I’d been living in for as long as I could remember - was sitting in front of me now, in a safe, warm,London pub, having a drink. While outside, people strolled up and down, buying cuff-links and remarking on the uncommonly fine weather.

I think you’d have wittered too.

We got back into the Ford, and I drove us around.

Sarah still hadn’t really said much, except that she was sure there was nobody following her, and I’d said good, that’s a relief, and hadn’t believed it for a second. So I drove around, and watched the rear-view mirror. I took us down narrow one-way streets, up leafy, car-free avenues, jinked from lane to lane on the Westway, and saw nothing. I thought hang the expense, and drove into, and straight out of, two multi-storey car-parks, which is always a nightmare for the following vehicle. Nothing.

I left Sarah in the car while I got out and checked for a magnetic transmitter, running my fingers under the bumpers and wheel arches for fifteen minutes until I was sure. I even pulled over a couple of times, and scanned the skies above for a clattering police helicopter.

Nothing.

If I’d been a betting man, and I’d had something to bet with, I’d have put it all on us being clean, untailed, and unwatched.

Alone in a quiet world.

People talk about nightfall, or night falling, or dusk falling, and it’s never seemed right to me. Perhaps they once meant befalling. As in night befalls. As in night happens. Perhaps they, whoever they were, thought of a falling sun. That might be it, except that that ought to give us dayfall. Day fell on Rupert the Bear. And we know, if we’ve ever read a book, that day doesn’t fall or rise. It breaks. In books, day breaks, and night falls.

In life, night rises from the ground. The day hangs on for as long as it can, bright and eager, absolutely and positively the last guest to leave the party, while the ground darkens, oozing night around your ankles, swallowing for ever that dropped contact lens, making you miss that low catch in the gully on the last ball of the last over.

Night rose on Hampstead Heath as Sarah and I walked together, sometimes holding hands, sometimes not.

We walked in silence mostly, just listening to the sounds of our feet on the grass, the mud, the stones. Swallows flitted here and there, darting in and out of the trees and bushes like furtive homosexuals, while the furtive homosexuals flitted here and there, pretty much like swallows. There was a lot of activity on the Heath that night. Or perhaps it’s every night. Men seemed to be everywhere, in ones, and twos, and threes and mores, appraising, signalling, negotiating, getting it done: plugging into each other to give, or receive, that microsecond of electric charge that would allow them to go back home and concentrate on the plot of an Inspector Morse without getting restless.

This is what men are like, I thought. This is unfettered male sexuality. Not without love, but separate from love. Short, neat, efficient. The Fiat Panda, in fact.

‘What are you thinking about?’ asked Sarah, staring hard at the ground as she walked.

‘About you,’ I said, with hardly a stumble.

‘Me?’ she said, and we strolled for a while. ‘Good or bad?’

‘Oh good, definitely.’ I looked at her, but she was frowning, still staring downwards. ‘Definitely good,’ I said again.

We came to a pond, and stood by it, and stared at it, and threw stones in it, and generally gave thanks for it according to whatever ancient mechanism it is that draws people to water. I thought back to the last time we had been alone together, on the banks of the river atHenley. BeforePrague, before the Sword, before all kinds of other things.

‘Thomas,’ she said.

I turned and looked at her head on, because I suddenly had the feeling that she’d been rehearsing something in her mind and now wanted to get it out in a hurry.

‘Sarah,’ I said.

She kept looking down.

‘Thomas, what do you say we make a run for it?’

She paused for a while, and then, at last, raised her eyes to me - those beautiful, huge, grey eyes - and I could see desperation in them, deep and on the surface. ‘I mean, together,’ she said. ‘Just get the hell out.’

I looked at her and sighed. In another world, I thought to myself, it might have worked. In another world, in another universe, in another time, as two quite different people, we really might have been able to put all of this behind us, take off to some sun-drenchedCaribbean island, and have sex and pineapple juice, non-stop, for a year.

But now, it wasn’t going to work. Things I’d thought for a long time, I now knew; and things I’d known for a long time, I now hated knowing.

I took a deep breath.

‘How well do you know Russell Barnes?’ I said. She blinked.

‘What?’

‘I asked you how well you knew Russell Barnes.’

She stared at me for a moment, then let out a kind of laugh; the way I do, when I realise I’m in big trouble.

‘Barnes,’ she said, looking away and shaking her head, trying to behave as if I’d just asked her whether she preferred Coke or Pepsi. ‘What the hell has that…’

I took hold of her by the elbow and squeezed, jerking her round to face me again.

‘Will you answer the fucking question, please?’

The desperation in her eyes was changing to panic. I was scaring her. To be honest, I was scaring myself.