'I'm hungry,' Vanessa said suddenly. 'How about you?'

'I don't think so,' Elder said, realising as he spoke it wasn't true.

They bought falafels from a stall and ate them in pitta bread, leaning up against the wall.

'How's it all going, anyway?' Vanessa said. 'The investigation.'

'Oh, you know.'

'Still stuck?'

'Pretty much. But something will open it, it usually does.'

She smiled. 'I don't think I've exactly been a great help.'

'No. You were right to tell me. Ginger, we'll check him out. Besides, it's a good falafel. Can't get this in Cornwall, you know. Pasties, that's about it.'

'Cream teas.'

'That too.'

A youth wearing an England soccer shirt and little else, despite the cold, lurched against them, apologised, and staggered on his way.

'I'd best be making a move,' Elder said, stepping clear.

'Okay.'

'How d'you get back from here, Tube?'

'Bus.'

They walked together towards the station.

'Take care,' she said at the entrance. 'Good luck.'

'You too.'

The street light shone bright on her face.

When Vanessa sidestepped the usual coterie of druggies and near-drunks on her way to the bus-stop, it's doubtful that she noticed the dark blue saloon illegally parked near the crossroads, the man watching her carefully from behind the wheel.

Elder slept fitfully, disturbed by dreams in which his daughter, like a dragonfly, sloughed off one skin to reveal another, her face and body becoming those of Maddy Birch, only to be replaced, as easily, by those of someone he didn't recognise, so that, when he woke, his hair was matted to his scalp, the quilt, sticky with sweat, tangled between his legs.

Clambering from the bed, he stood for fully five minutes under the shower, warm water washing over head and shoulders as he soaped himself clean; a final burst of cold, face raised, as if to purge himself before stepping clear.

Coffee, toast, a white shirt more or less uncreased from the hanger, navy blue trousers, the same comfortable, well-worn shoes; yesterday's shirt and boxer shorts he stuffed into the washing machine, along with the quilt cover and pillowcase.

When he dialled Joanne's number, hoping to speak to Katherine, all he got was an automated voice requesting that he leave a message.

Someone in the flat below was treating him to Capital Gold and he countered with Radio 3. Haydn, probably. Wasn't it usually Haydn? Mozart or Haydn. Maybe Bach.

A chapter of Patrick O'Brian – enemy vessel at four o'clock on the horizon, run out the guns, run up the flag – and he was ready for something altogether drier. Scooping up his mobile just in case, he slipped it into his pocket; the 'Grant Inquiry Report', notebook and ballpoint were all ready to go. The A-Z he checked in the car.

No space in the small car park close to Kenwood House, so he parked on Hampstead Lane. Most of the tables outside the cafe were taken, Sunday broadsheets spread wide. The weather was kind. He found a space towards the rear corner, broke off a piece of his almond croissant, tasted his coffee and began to read. Somehow, the hum of other voices around him made concentration easier.

Ashley and his team, it seemed, had gone about their task with thoroughness if not inspiration; reading between the lines, it was clear certain sections of the Met had not made their task any easier than was necessary. The report's conclusions, which laid down a modicum of organisational blame but nothing else, were unexceptional. In the matter of James Grant and the second gun, Detective Superintendent Mallory had been given the benefit of any possible doubt.

Elder thought a few words with Trevor Ashley might not be out of place.

Taking out his mobile phone, he tried Joanne again with the same result.

The residue of his coffee was cold.

When he had himself been an officer in the Met and stationed in West London, he and Joanne had driven to Hampstead Heath with Katherine one Sunday afternoon and flown her kite from the top of Parliament Hill. Katherine – five then, or was she six? – had lost patience and run down the slope towards the children's playground and the paddling pool, Elder scrambling after her, laughing, while Joanne reeled in the kite's thin line.

Had she already been sleeping with Martyn Miles by then?

Some truths it was better not to know.

22

Grey Monday. The previous day's wintry sunshine had flattered to deceive. Karen Shields was at her desk, advancing a batch of circulars and memos towards the shredder. Elder had stopped off at the coffee machine on the way.

They sat either side of Karen's desk, the hubbub of the day ringing around them.

'How was your Sunday?' Karen asked.

'Nothing special. You?'

'Much the same.' Karen had slept in as long as she could, before meeting one of her friends on Upper Street for brunch, followed by a so-so movie at the Screen on the Green. In the evening, she'd watched TV, washed clothes, ironed, spoken to her sister in Stockwell, her mother in Jamaica.

'One thing I did do,' Elder said, 'read through the report on the Grant shooting.'

'Anything there for us?'

'Not that I could see right away. Pretty straightforward, really.'

'Dead end, then?'

'Probably.' Elder sipped his coffee through a hole in the lid. 'Might be worth contacting Ashley, the Herts. Super who ran the inquiry. Just for a chat. Talk things through.'

'A little help reading between the lines.'

Elder grinned. 'Something like that.'

How he could drink his coffee that hot, she didn't know. 'Mike and I checked out the last couple of possibles from the Sex Offenders Register.'

'Anything?'

Karen shook her head. 'Could have saved ourselves the trouble. Elderly rapist with diabetes and a dodgy hip, and a twice-convicted sexual predator incapacitated by the onset of Aids.'

'Oh, well. Tick 'em off and move on.'

'Where to?'

Elder set his cup on the edge of the desk. 'Vanessa Taylor?'

'What about her?'

He gave Karen the gist of what Vanessa had told him on Saturday evening.

Karen gave it a few moments' thought. 'Mallory and Repton, what do you think? They were just winding her up for the sake of it? Playing games?'

'It's possible. But, no, I think there's more to it than that.'

'And it goes back to Grant?'

'So it would seem.'

'Grant and Maddy.'

'Yes. Somehow.'

'Which is why you want to talk to Ashley.'

'Correct.'

'A little more than just a casual chat, then?'

Elder smiled. There was a sudden flurry of telephones in the middle distance. Raised voices. Someone urgently, repeatedly swearing.

'What about this other thing she mentioned?' Karen said. 'This ginger Lothario from Firearms?'

'Tracing him shouldn't be too hard.'

'You don't think it's clutching at straws?'

'I think right now we clutch at anything we can.'

Karen knew he was right. 'I'll get Mike and Lee on to it.' When she tried her coffee again, it was just okay to drink. 'By the way, Maddy's missing watch, I had the inventory double-checked in case there'd been some kind of clerical error. But no, no sign.'

'I asked her mother about it at the funeral,' Elder said. 'Apparently her father gave her the watch years ago. A Lorus. Nothing fancy. Water-resistant. Stainless steel. Maddy's name engraved on the back. And the date: fifteenth of the seventh, 1981.'

'Her twenty-first,' Karen said, doing the sums in her head.

'Yes.'

A brief image of Katherine flickered behind Elder's eyes.

'Vanessa confirmed,' he said, 'that was the watch Maddy still wore.'