Marcus parked the car a couple of doors down from 'Hillview'. No cars outside, no cars in the drive. No sign oflife. No proof of it at all.

'You can have the honours,' Louise said to Marcus when they got out of the car and he stepped forward and knocked smartly on the door.

'Very professionally done,' Louise said. 'You should be a policeman.'

A big, deeply unattractive man in a white wife-beater vest opened the door and stared unwelcomingly at them. She could hear a racing commentary blaring from a television somewhere in the background. He had a can of lager in one hand and a cigarette in the other. He was a formidable cliche, Louise felt like congratulating him on his near-iconic status.

'Good afternoon,' Marcus said pleasantly. 'I wonder if you could help us?' He sounded like an evangelist doorstep-selling good news and Bibles.

'Unlikely,' the missing link said. Louise couldn't tell ifhe was being insolent or just being English. Both, probably. Her warrant itched in her bag but they were in mufti, not here on official business.

'I'm looking for a Mrs Agnes Barker?' Marcus persisted pleasantly. 'Who?'The man frowned at Marcus as if he'd started speaking in tongues. 'Agnes Barker,' he repeated slowly. 'This is the address we have for her.'

'Well, you're wrong.'

Louise couldn't help herself. She pulled her warrant out and thrust it in his ugly face and said, 'Shall we try that again? From the top _. we're looking for a Mrs Agnes Barker.'

'I don't know,' he said truculently. 'I rent. I'll give you the number.'

'Thank you.'

The girl who answered the phone at the rental agency and who sounded about twelve years old readily admitted that they were handling the rental for Mrs Barker's solicitor without Louise even explaining who she was. 'They have a power of attorney for her,' she said, which Louise translated as meaning that the aunt was gaga.

'Mrs Barker is incapacitated?'

'She's in Fernlea. It's a nursing home.'

'So she does exist,' Marcus said.

Louise's phone rang as Marcus was reprogramming the Sat Nav. Abbie Nash was saying, 'Boss? Got something on the car rental, or rather got nothing. We've phoned round every car hire place in Edinburgh. None of them rented a vehicle to a Joanna Hunter.'

'Perhaps she never changed the name on her driving licence when she married.'

'Mason?' Abbie said. 'Yep, tried that. Zilch on that too. But while we were on the phone I thought I might as well run Decker's name, just in case, you know, and -bingo. Decker hired a Renault Espace this morning. And this is interesting -he was with his daughter.'

'He doesn't have a daughter.'

'That's why it's interesting.'

'The plot thickens,' Marcus said happily when Louise relayed this information to him.

Fernlea was everything Louise feared for herself. The high-backed chairs gathered in the lounge around the television, the smell of institutional cooking layered over a faint but prevalent scent of Izal. It didn't matter that there was a noticeboard displaying activities for the residents (Carpet bowls) and outings (Harlow Carr Gardens, Harrogate, including lunch at Betty's!), it remained a place to send people who nobody wanted. A place to die. Archie would send her somewhere like this, when she was toothless and bald, wetting herself, forgetting her own son's name. She wouldn't blame him. Patrick wouldn't look after her, he was a man, so statistically he was likely to be dead, despite his golf and his red wine and his swimming.

She wasn't coming here. She would step out of her life, she would walk out into a cold, cold night (I may be some time), lie down beneath a hedge and go to sleep rather than come to a place like this. Or slit her wrists and wait, as composed as a Roman. Or get a gun -easy enough -and put it in her mouth as if it were a liquorice stick and blow her brains out of the other side of her head. Part of her was almost looking forward to it. There was something to be said for dying before you ended up in incontinence pads, watching an endless loop of reruns of Friends. Gabrielle Mason, Patrick's Samantha, Alison Needler's sister, Debbie. Preserved in the amber of memory, forever young. Forever dead.

In the reception area, Louise showed her warrant and her politest smile and said, 'Just need to have a word with Mrs Barker,' to a heavy girl in a pink-and-white gingham check uniform that was too tight, revealing rippling rolls of fat trying to escape. Sausage in a skin. 'Hayley', her plastic name badge said. Hayley's thin fair hair was scraped back into a scrunchy, leaving her moon face mercilessly exposed. She made cow eyes at Marcus who politely ignored her.

The girl struggled to liberate a bar of chocolate from a pocket in her uniform. She unwrapped it and offered a piece to Louise. The chocolate was flattened and slightly melted and Louise waved it away even though she wanted it. Marcus took a piece and the girl blushed. She reminded Louise of a sugar-pig. She used to like sugar-pigs. 'Do you think she'll be up to having a chat?' she said.

'I doubt it,' the girl said.

'Because she's not lucid?'

'Because she's dead.'

Yeah, Louise thought. Death did have a way of shutting you up.

An Elderly Aunt, exit stage right.

'Recently?' Marcus asked. 'A couple ofweeks ago. Massive stroke,' the girl volunteered, popping the last piece of chocolate into her mouth. 'Someone should tell her solicitor,' Louise said, more to herself than the girl. Come to that, someone should tell Neil Hunter. 'Did she have family?' 'I think there might have been a nephew or a niece but they were, you know, what's it called? Like "strangled".'

'Estranged?'

'Yeah, that's the word. Estranged.'

'She doesn't exist. The aunt is no more,' Marcus said to Louise as they left Fernlea's unhallowed halls behind. 'The aunt has ceased to be, she is an ex-aunt. If the plot got any thicker it would be solid, eh, boss?'

'You drive, Scout,' Louise said generously. Her headache was beginning to make her feel sick.

'So now what, boss?'

'I haven't got a scooby. Might buy some cheese. No, wait, get on the phone and tell someone to find out who visited Decker in prison in the last year. He walks away from a train crash and hires a bloody big car with a so-called daughter. Find out who the daughter really is. Someone must be helping him.'

'Unless he just picked the girl up. Unless he took her against her will.'

'Jesus,' Louise said. 'Don't go there.'

'Do you think Decker might have something to do with the aunt?' Marcus puzzled. 'I don't know who has anything to do with who any more.' There was no aunt, that at least was one incontrovertible fact. So either Joanna Hunter had lied to her husband about her destination (Must pop down to see poor old Aunt Agnes) or he had lied to everybody else (She's gone to see a sick aunt). And who was the most likely liarNeil Hunter or the lovely Dr Hunter? Actually, Louise wasn't sure she knew the answer to that question. She suspected that if push came to shove Joanna Hunter could dissemble with the best of them.

She had run and hidden once, now she was doing it again. She must have been upset by Decker's release. She was the same age as her mother when she was murdered, her baby was the same age as her brother. Might she do something stupid? To herself? To Decker? Had she nurtured revenge in her heart for thirty years and now wanted to execute justice? That was an outlandish idea, people didn't do that. Louise would have done, she would have made dice of Decker's bones, catmeat of his heart, pursued him to the end of time, but Louise wasn't like other people. Joanna Hunter wasn't like other people either though, was she?

They parked in the centre of Hawes and Louise got out and wandered over to a bridge and gazed down at the water. She felt adrift, Louise Unbound. Joanna had walked out of her life with nothing (except the baby, which was everything) and disappeared. It was a trick that you might envy. Joanna Hunter, the great escapologist.