I am not a courageous man, and I never have been: so I'm afraid of what may happen to me tonight. But I cannot go through life dreaming all the time, existing through the darkness on only a glimpse of heaven. Sooner or later, one has to gird one's loins (that's appropriate) and get up and find it. Even if it means giving away the world in exchange.

I probably make no sense. You're thinking, you who chanced on this testimony, you're thinking, who was he, this imbecile?

My name was Oliver Vassi. I am now thirty-eight years old. I was a lawyer, until a year or more ago, when I began the search that ends tonight with that pimp and that key and that holy of holies.

But the story begins more than a year ago. It is many years since Jacqueline Ess first came to me.

She arrived out of the blue at my offices, claiming to be the widow of a friend of mine from Law School, one Benjamin Ess, and when I thought back, I remembered the face. A mutual friend who'd been at the wedding had shown me a photograph of Ben and his blushing bride. And here she was, every bit as elusive a beauty as her photograph promised.

I remember being acutely embarrassed at that first interview. She'd arrived at a busy time, and I was up to my neck in work. But I was so enthralled by her, I let all the day's interviews fall by the wayside, and when my secretary came in she gave me one of her steely glances as if to throw a bucket of cold water over me. I suppose I was enamoured from the start, and she sensed the electric atmosphere in my office. Me, I pretended I was merely being polite to the widow of an old friend. I didn't like to think about passion: it wasn't a part of my nature, or so I thought. How little we know — I mean really know —about our capabilities.

Jacqueline told me lies at that first meeting. About how Ben had died of cancer, of how often he had spoken of me, and how fondly. I suppose she could have told me the truth then and there, and I would have lapped it up — I believe I was utterly devoted from the beginning.

But it's difficult to remember quite how and when interest in another human being flares into something more committed, more passionate. It may be that I am inventing the impact she had on me at that first meeting, simply re-inventing history to justify my later excesses. I'm not sure. Anyway, wherever and whenever it happened, however quickly or slowly, I succumbed to her, and the affair began.

I'm not a particularly inquisitive man where my friends, or my bed-partners, are concerned. As a lawyer one spends one's time going through the dirt of other people's lives, and frankly, eight hours a day of that is quite enough for me. When I'm out of the office my pleasure is in letting people be. I don't pry, I don't dig, I just take them on face value.

Jacqueline was no exception to this rule. She was a woman I was glad to have in my life whatever the truth of her past. She possessed a marvellous sang-froid, she was witty, bawdy, oblique. I had never met a more enchanting woman. It was none of my business how she'd lived with Ben, what the marriage had been like etc., etc. That was her history. I was happy to live in the present, and let the past die its own death. I think I even flattered myself that whatever pain she had experienced, I could help her forget it.

Certainly her stories had holes in them. As a lawyer, I was trained to be eagle-eyed where fabrications were concerned, and however much I tried to put my perceptions aside I sensed that she wasn't quite coming clean with me. But everyone has secrets: I knew that. Let her have hers, I thought.

Only once did I challenge her on a detail of her pretended life-story. In talking about Ben's death, she let slip that he had got what he deserved. I asked her what she meant. She smiled, that Gioconda smile of hers, and told me that she felt there was a balance to be redressed between men and women. I let the observation pass. After all, I was obsessed by that time, past all hope of salvation; whatever argument she was putting, I was happy to concede it.

She was so beautiful, you see. Not in any two dimensional sense: she wasn't young, she wasn't innocent, she didn't have that pristine symmetry so favoured by ad-men and photographers. Her face was plainly that of a woman in her early forties: it had been used to laugh and cry, and usage leaves its marks. But she had a power to transform herself, in the subtlest way, making that face as various as the sky. Early on, I thought it was a make-up trick. But as we slept together more and more, and I watched her in the mornings, sleep in her eyes, and in the evenings, heavy with fatigue, I soon realized she wore nothing on her skull but flesh and blood. What transformed her was internal: it was a trick of the will.

And, you know, that made me love her all the more.

Then one night I woke with her sleeping beside me. We slept often on the floor, which she preferred to the bed. Beds, she said, reminded her of marriage. Anyway, that night she was lying under a quilt on the carpet of my room, and I, simply out of adoration, was watching her face in sleep.

If one has given oneself utterly, watching the beloved sleep can be a vile experience. Perhaps some of you have known that paralysis, staring down at features closed to your enquiry, locked away from you where you can never, ever go, into the other's mind. As I say, for us who have given ourselves, that is a horror. One knows, in those moments, that one does not exist, except in relation to that face, that personality. Therefore, when that face is closed down, that personality is lost in its own unknowable world, one feels completely without purpose. A planet without a sun, revolving in darkness.

That's how I felt that night, looking down at her extraordinary features, and as I chewed on my soullessness, her face began to alter. She was clearly dreaming; but what dreams must she have been having. Her very fabric was on the move, her muscle, her hair, the down on her cheek moving to the dictates of some internal tide. Her lips bloomed from her bone, boiling up into a slavering tower of skin; her hair swirled around her head as though she were lying in water; the substance of her cheeks formed furrows and ridges like the ritual scars on a warrior; inflamed and throbbing patterns of tissue, swelling up and changing again even as a pattern formed. This fluxion was a terror to me, and I must have made some noise. She didn't wake, but came a little closer to the surface of sleep, leaving the deeper waters where these powers were sourced. The patterns sank away in an instant, and her face was again that of a gently sleeping woman.

That was, you can understand, a pivotal experience, even though I spent the next few days trying to convince myself that I hadn't seen it.

The effort was useless. I knew there was something wrong with her; and at that time I was certain she knew nothing about it. I was convinced that something in her system was awry, and that I was best to investigate her history before I told her what I had seen.

On reflection, of course, that seems laughably naive. To think she wouldn't have known that she contained such a power. But it was easier for me to picture her as prey to such skill, than mistress of it. That's a man speaking of a woman; not just me, Oliver Vassi, of her, Jacqueline Ess. We cannot believe, we men, that power will ever reside happily in the body of a woman, unless that power is a male child. Not true power. The power must be in male hands, God-given. That's what our fathers tell us, idiots that they are.

Anyway, I investigated Jacqueline, as surreptitiously as I could. I had a contact in York where the couple had lived, and it wasn't difficult to get some enquiries moving. It took a week for my contact to get back to me, because he'd had to cut through a good deal of shit from the police to get a hint of the truth, but the news came, and it was bad.