A couple of years ago, not long after she met Patrick and when Archie's behaviour was at its most worrying, she had gone for therapy, something she had always sworn she would never do. Never say never. She did it for Archie, thinking that his problems must be a result of hers, that if she could be a better mother his life would improve. And she did it for Patrick too because he seemed to represent a chance for change, to become like other people.

It was cognitive behavioural stuff that didn't delve too deeply into the murk of her psychopathology, thank God. The basic principle was that she should learn to avoid negative thinking, freeing her to have a more positive attitude to life. The therapist, a hippyish, wellintentioned woman called Jenny who looked as if she'd knitted herself, told Louise to visualize a place where she could put all her negative thoughts and Louise had chosen a chest at the bottom of the sea, the kind that was beloved ofpirates in storybooks -hooped and banded with metal, padlocked and hasped to keep safe, not treasure, but Louise's unhelpful thoughts.

The more detailed the better,Jenny said, and so Louise added coral and shells to the gritty sand, barnacles clinging to the sides of the chest, curious fishes and sharks nosing it, lobsters and crabs crawling all over it, fronds ofseaweed waving in the tidal currents. She became an adept with the locks and the keys, could visit her underwater world at the flick ofa mental switch. The problem was that when she had safely locked up all the negative thoughts at the bottom of the sea there was nothing else left, no positive thoughts at all. 'Guess I'm just not a positive person,' she said to Jenny. She thoughtJenny would protest, pull her to her maternal, knitted bosom and tell her it was just a matter of time (and money) before she was fixed. But Jenny agreed with her and said, 'I guess not.'

She stopped going to Jenny and not long after she accepted Patrick's proposal.

Archie went to Fettes now. Two years ago at the age of fourteen he had been on the edge of something bad, it had only been some petty thieving, some bunking off school, trouble with the police (oh, the irony) but she could tell, because she'd seen it enough times in other teenagers, that ifit wasn't nipped in the bud it wouldn't just be a phase, it would be a way of life. He was ready for a change or it wouldn't have worked. She used her mother's life insurance to pay his exorbitant school fees, 'So the drunken old cow's good for something at last,' Louise said. The school was the kind ofplace that Louise had spent her red-flagged life railing against -privilege, the perpetuation of the ruling hegemony, yada, yada, yada. And now she was subscribing to it because the greater good wasn't an argument she was going to deploy when it came to her own flesh and blood. 'What about your principles?' someone said to her and she said, 'Archie is my principles.'

The gamble had paid off. Two years later and he had gone from Gothic to geek (his true metier all along) in one relatively easy move and now hung about with his geek confreres in the astronomy club, the chess club, the computer club and God knew what other activities that seemed entirely alien to Louise. Louise had an MA in literature and she was sure that if she'd had a daughter they would have had great chats about the Brontes and George Eliot. (While what? They baked cakes and did each other's make-up? Get real, Louise.)

'It's not too late,' Patrick said.

'For what?'

'A baby.'

A chill went through her. Someone had opened a door in her heart and let in the north wind. Did he want a baby? She couldn't ask him in case he said yes. Was he going to seduce her into it, like he'd seduced her into marriage? She already had a child, a child who was wrapped around her heart and she couldn't walk on that wild shore again.

All her life she had been fighting. 'Time to stop,' Patrick said, massaging her shoulders after a particularly gruelling day at work. 'Lay down your arms and surrender, take things how they come.'

'You should have been a Zen master,' she said.

'I am.'

She hadn't expected ever to hit forty and suddenly find herself in a two-car family, to be living in an expensive flat, to be wearing a rock the size of Gibraltar. Most people would see this as a goal or an improvement but Louise felt as if she might have taken the wrong road without even noticing the turning. Sometimes, in her more paranoid moments, she wondered if Patrick had somehow managed to hypnotize her.

She had changed their insurance policy when they moved and the woman on the other end of the phone went through all the standard questions -age of the building, how many rooms, is there an alarm system in place -before asking, 'Do you keep any jewels, furs or shotguns on the premises?' and for a moment Louise felt an unexpected thrill at the idea of a life containing those elements. (She'd made a start -she had the jewel.) She had clearly missed her way, parcelled everything up, nice and neat, settled down, when the real Louise wanted to be out there somewhere living the outlaw life, wearing jewels and furs, toting a gun. Even the idea of furs didn't worry her that much. She could shoot something and skin it and eat it, better than the unfeeling distance between the abattoir and the soft, pale packages at the Waitrose meat counter.

'No,' she said to the woman at the insurance company, returning to sobriety, 'only my engagement ring.' Twenty thousand pounds' worth ofsecond-hand bling. Sell it and run, Louise. Run fast. Joanna Hunter had been a runner (was she still?) , a university athletics champion. She had run once and it had saved her life, perhaps she had made sure that no one was ever going to catch her. Louise had read the noticeboard hanging in the Hunters' kitchen, the little everyday trophies and mementoes of a life -postcards, certificates, photographs, messages. Nothing of course about the event that must have shaped her entire existence, murder wasn't something you tended to pin up on your kitchen corkboard. Alison Needler, on the other hand, didn't run. She hid.

Louise hardly saw Archie now. He had elected to board during the week because he would rather live in a school than with his mother. At weekends he sought out the same boys he spent all week at school with.

'Stop fretting,' Patrick said. 'He's sixteen, he's spreading his wings.'

Louise thought of Icarus.

'And learning to fly.'

Louise thought of the dead bird she had found outside the flat at the weekend. A bad omen. Little cock sparrow shot by a boy with a bow and arrow.

'He has to grow up.'

'I don't see why.'

'Louise,' Patrick said gently, 'Archie's happy.'

'Happy?' Happy wasn't a word she had employed in the context of Archie since he was a little boy. How wonderfully, joyously untrammelled he had been then in his happiness. She thought it was fixed for ever, didn't realize that childhood happiness dissolves away, because she herself had never known happiness as a child. If she had realized that Archie wasn't going to be that sunny innocent for ever she would have laid up every moment as treasure. Now she could have it again if she wanted. The north wind howled. She shut the door.

She was on her way back from a meeting with the Amethyst team out at the Gyle. That was how Louise first came across Alison Needler, six months before the murders, when she was seconded for a few months to Amethyst, the Family Protection Unit. David Needler, defYing the court injunction against him, had taken up a position on the family lawn in Trinity where he was threatening to set himself alight with his kids and ex-wife watching from an upstairs window. When Louise arrived, hot on the heels of the Instant Response Vehicle, he was being berated by Alison's sister Debbie, standing on the front doorstep. ('Lippy, our Debs,' according to Alison. Well, she paid the price for that, didn't she?) Taunted, perhaps, rather than berated (' Go on then, you bastard, let's see you torch yourself.).