My heart was squeezed every time I thought of the word 'Urgent'. There was something about it. I couldn't pretend to myself that Cannon just wanted a chat for old times' sake.

I took the Central Line home and tried to put my flat in order. I wrote cheques for a couple of utility bills; I turned off the boiler and made sure all the windows were double-locked. I took the photobooth picture of Jennifer with Anne out from my desk drawer, took it over to the window overlooking the garden square and looked at it.

There she was: my fate, my self. I kissed her face. Or rather, I kissed the cheap photopaper that had been squeezed damp from the side of the machine. I felt no remorse or sadness.

Then I took my file of newspaper cuttings about Jen's disappearance and put a match to them in the fireplace.

After a moment's hesitation, I threw the picture in as well. Now she was gone. The edge didn't curl up as it's meant to; but I did see Jen's eyes look into mine one last time. I felt as though someone was prising my ribs apart with their bare hands.

When everything was quite burned, I swept the ashes out and emptied the pan down the toilet, which I flushed until every speck was gone.

I wondered what to do about Margaret. Best to find out what Cannon wanted first. I dialled the number and after being put on hold for a minute, got through to a young woman.

'Can I speak to Chief Inspector Cannon, please?'

'Who's speaking, please?'

'Michael Watson.'

'Will he know what it's in regard to?'

I breathed in hard. 'I'm not able to predict that.'

'Pardon?'

'I'm returning his call.'

There was a pause, then suddenly Cannon was on the line.

'Mr Engleby. Thank you for calling back.' He sounded exhilarated. 'We've had the devil's own job tracking you down. Thank goodness for your old school. They pointed us in the right direction.'

Cannon had become more confident with age; he'd also acquired a bit of bogus golf-club polish to his voice.

'Good,' I said.

'I expect you know what I'm calling in connection with.'

'Not really.'

'The case of Jennifer Arkland. I'm sure you remember.'

'Yes. Of course.'

'One or two things have come to light. I'd very much like to talk to you again. I'd like you to come up here and see me.'

'I can't come today.'

'Yes, you can, Mr Engleby. I'm sending a car for you. Are you at home?'

'Yes.'

'My man will be with you in a few minutes. I didn't come to your newspaper because I didn't want to make a scene in front of your colleagues. I have been requested by the family to play this very low key for reasons of press and publicity. In return for that, I'd appreciate your full co-operation. Please don't leave your house. Otherwise I shall issue a warrant for your arrest. I can play it rough if you prefer.'

'I understand.'

I put the phone down. I felt all right. He wasn't arresting me; it was all quite amicable. If they really thought I'd killed Jennifer, if they really had hard evidence, they'd have marched in and grabbed me. They'd have taken no chances. That's how the plods operate.

I called Margaret at work and told her I was going to Edinburgh and that I'd ring the next day. She received this news coolly, but things were not that good between us since I'd been spending less time in Holloway. I was relieved that she wasn't too inquisitive.

The bell rang and two reasonable policemen took me away to a tactfully unmarked maroon Volvo. We stopped for a sandwich and fizzy orange drink at a garage in East Finchley before we hit the North Circular. By two o'clock I was seated in the interview room in Mill Road police station.

A constable in shirtsleeves sat with me, saying nothing. I had a cup of tea in a styrofoam cup. I asked if I could smoke and he nodded, so I lit up a Rothman's, knocking the ash into a little tin ashtray on the table. One wall was clouded gla.s.s and I presumed it was a one-way, though that seemed a bit hi-tech for Mill Road. There was a ca.s.sette recorder on the table, housed in an odd, non-commercial wooden box.

What was I thinking as I waited? I don't know. Does one ever really think? I seemed just to drift through it. In order to keep itself functioning under pressure, the brain releases chemicals that make the bizarre and the frightening seem normal. The Nat Sci Tripos taught me that h.o.m.o saps who did not have this brain function were unsuccessful in reproduction, presumably because they couldn't handle stress and got themselves killed a lot by animals or other saps. So we who were chosen, we survivors, have it in spades.

Oddly enough, it can work too well. It can sometimes render crises not just normal or dealable-with, but strangely flat. I had to keep on reminding myself to stay alert that I was in danger.

Cannon came in, all beer belly and bl.u.s.ter. He shook my hand, sat down and lit up with orange fingers.

'See you haven't stopped either,' he said with a grin. This was a false note because he didn't know I smoked; I hadn't had one when he came to my room in college. He hadn't offered me one.

He swung his feet up onto the table. He was wearing brown suede shoes with uneven wear to the soles.

'So let's have a chat about Jennifer, shall we, Mike? Hang about. Better turn the old squawkbox on, hadn't we? Is there a tape in, John? Jolly good. Here we go then. Date, 19 June, 1988. Time 14.24 hours. Those present...'

'What happened to Peck?' I said.

'I beg your pardon?'

'Peck. The policeman who was in charge before.'

'He took early retirement on health grounds. He lives in Huntingdon. Follows the case, though. Anyway, Mike, I've been having a little think about you. Why did you change your name to Watson?'

'I got a job for a magazine, but they wanted to hire women. So I took the name Michele Watt. It was a joke. It was a mixture between my own first name and the surname of a famous scientist.' I paused. 'James Watt. But the magazine misprinted it as "Watts". Then eventually it wasn't necessary to pretend to be a woman any more. And I moved to another paper, where I wanted to be a man again, but my professional ident.i.ty was sort of bound up with this Michele Watts, so I just changed it as little as I could to make a clean start.'

Cannon looked at me, then at the tape machine, as though to make sure it had got all that down OK. He raised an eyebrow.

'So you pretended to be a girl, then there was a misprint, then you pretended to be someone else again. Have I got that right?'

'More or less.'

'I see. It wasn't because you were trying to disguise who you really were?'

'Why would I do that?'

'Did you change your name by deed poll?'

'No.'

'But you have credit cards in the name of M.K. Watson.'

'Yes.'

'That's a fraud, Mike, isn't it?'

'It's harmless.'

'Ever been in trouble with the police under either of your names?'

'No.'

'Never caught, were you? I asked around the shops a bit. At the time Jennifer disappeared. I showed your picture to a few people. Off-licences and that. I noticed the booze in your room vermouth and gin and I wasn't sure how a boy on a full grant could afford it.'

'I worked in the holidays.'

'Some of the shopkeepers weren't happy with you.'

I didn't say anything. I thought carefully. I could say, 'I don't have a record'; but I didn't see how that would help. So I stayed silent.

'I've done a lot of checking, in fact,' said Cannon. 'You became a bit of a hobby of mine, to tell the truth, Mike. I've had my eye on you off and on for all these years. You know, it's like blokes you were at school with. You're not in touch all the time, but out of the corner of your eye, you're sort of aware of what they're up to. Know what I mean?'

I nodded.

'Now let's talk about Jennifer, shall we?'

'OK.'

'Were you her boyfriend?'

'In a way.'

'What way? Were you having s.e.x with her?'

'That's none of your business.'

'Quite a few boys did have s.e.x with her, didn't they?'

'I don't think so.'

'According to what I read in the papers.'

'I wouldn't believe that stuff.'

'Well, you should know! Anyway, I didn't necessarily believe it either. So I went to check it out for myself.'

I could see that Cannon was trying to rile me.

'Oh yes,' he said, lighting up another Emba.s.sy, 'quite a hot little number, our Jennifer.'

I didn't rise to it. It wasn't true. One problem with her and Robin had been what she called 's.e.x, lack of'. Of course Cannon couldn't know this, because he hadn't read her diary.

I smiled, confident in my superior knowledge.

'A boy in King's and a boy in Downing both said-'

'Both lying,' I said. 'Just schoolboy braggarts. Perhaps they kissed her at a party and they wished they'd gone the whole way.'

Cannon stood up and went to a drawer in a desk in the corner of the room. From it, he took a plastic bag containing a large padded envelope, addressed to Jennifer's mother in Lymington.

'Do you recognise this?' he said.

I shook my head.

'Someone sent it to Jennifer's mother. It contained her diary.'

I nodded. It was not a time to speak.

'There aren't any fingerprints on it,' said Cannon. 'Maybe whoever sent it wore gloves.'

'Have you read the diary?'

'Oh yes.'

'And was it helpful to you?'

'Very much so, thank you, Michael. Now I wonder why whoever sent this diary to Mrs Arkland did send it. Do you think he was suffering from a bad conscience?'

I shrugged.

'Anyway, there are just traces of possible prints on the diary itself.'

'Won't they be Jennifer's?'

'Could be. Hard to tell. She hasn't got any fingers left. Just bones.'

There was a pause.

'So,' I said, 'had this diary been with her flatmates or what?'

Cannon laughed. 'You're a bit late with that, aren't you, Mike? It's as though you knew knew it had been missing.' it had been missing.'

'No, I didn't. I didn't even know she kept a diary.'

'You were her boyfriend and you didn't know she kept a diary?'

'I didn't see her every day.'

'Listen, Mike, I'm going to give you a chance. I'm going to let you make a clean breast of the whole thing. It'll be in your best interests. It'll play really well in court. Remorse, regret. You can talk about the strain of exams and student life and all that. You'll get life, you could be out in ten, twelve years. You'll only be about my age. It's nothing.'