'Don't forget your inhaler, Theo,' bossed Scarlet, taking it out of the sponge bag.

'I didn't know you had asthma,' said Joseph. 'How could I not have known that?'

Theo seemed embarrassed. 'No big deal. I hardly ever get ill anymore. I don't even need to use this every day; the doctor says I can stop soon.'

The three went to bed at intervals, in order of age. Scarlet explained that this was what happened at home, and Joseph tried not to wince. Ben and Theo had a squab each in the sitting room, but Scarlet was in the lap of luxury-a double bed that was made by removing the table and pulling a sliding panel from underneath the seats.

Joseph read stories for an hour, choosing them at random from the bookshelf. He could not stop thinking about the slender fingers that had last turned those pages. He heard the water-clear voice, lilting and laughing at Roald Dahl's foul-mouthed Goldilocks.

Finally, he put the books away. For a time he strolled around, picking up toys and clothes. He had the radio playing by the sink as he made his last round, bending to kiss each child. Ben was asleep at last, his round cheek sinking into the pillow and long eyelashes fluttering. Joseph lingered, savouring his son's warmth. The radio station had begun playing back-to-back classic hits. Abba was merrily crooning a sad song about Chiquitita. Joseph hummed along for a few bars.

'You have a nice voice,' called Scarlet from her bed by the kitchen, 'but that song's as old as the hills.'

''Night, Dad,' murmured Theo.

Joseph felt the airbag swelling in his chest. 'It's nice to have you here, Theo,' he whispered. 'Much more than nice.'

'I'll get out my football tomorrow.'

'Great!'

Theo snuggled under his cover. 'Maybe we could have a bit of a game.'

'It's a fixture.'

Abba finished their song, and another merged into its closing bars. Leonard Cohen's gravelly depth, this time. Ah, yes. 'Hallelujah'. Zoe would have approved. She'd been a fan of Leonard Cohen, and this song was her favourite. Joseph could see her now, swaying to the slow rhythm, reaching out for his hands with the smile he could never resist. He watched her longingly for a moment. Then he ruffled Theo's hair.

'Sleep well,' he said. 'I'll just be through that door if you need me.'

As he straightened, he heard a muffled scream from Scarlet's bed. He was beside her in less than a second. She was curled under the duvet, gasping for breath.

'Scarlet!' he cried, horrified. 'What is it?'

'Make it stop, make it stop!' she shrieked, covering her ears.

'Stop what?' Joseph felt helpless. She was obviously acutely ill, having some kind of fit. Epilepsy? Meningitis? Psychosis, like her mother? Please God, no.

'Stop him!' She was panicking, really panicking, her face and hair wet with tears. This was a different girl altogether from the composed young adult who'd helped him make the beds and handed her brother his inhaler. This poor child knew terror. Joseph reached out to touch her head, but she jerked away as though he'd electrocuted her.

'I don't understand,' he cried helplessly. 'What do I do?'

Suddenly she was on her feet. She lunged at the radio, snatching it, frantically pressing every button. When this failed to stop the music, she hurled it onto the floor. Joseph swiftly picked it up and twisted the volume dial.

Leonard Cohen was silenced.

Theo was sitting up in bed, looking frightened. Scarlet stood rocking, a thin figure in the middle of the floor, her arms wrapped around her chest.

'Oh my God,' she sobbed. 'Oh my God, oh my . . . It was the man. The devil man.'

'What man?' Joseph asked. 'Who? I don't understand.'

Then it came to him, in a rush of icy memory. Leonard Cohen, singing 'Hallelujah'. A beautiful song. Zoe's favourite.

She often played it. She often danced to it.

She even died to it.

The caravan was submerged in darkness. Inside, the two boys slept soundly under bedding that their mother drove all the way to York to buy, on one of her last ever spending sprees. The duvets were goose down, and their covers matched the pillowcases: birds of paradise in a hundred vibrant colours. Zoe knew how to make life look beautiful.

There was no moon. No stars, either. The clear evening had given way to rain so fine and light that it was almost a mist, pattering its wet fingers dully on the roof and trickling in the guttering. Father and daughter sat on the top step of the caravan, under the awning. She was wearing his heavy overcoat, boyish hair half-hidden beneath the collar. Mugs steamed on the step beside them: chocolate in hers, tea in his. They each fidgeted with garish wands of light.

Joseph found his voice. 'I'm so sorry.'

She turned her stick this way and that, watching the trail of mauve.

'That was the soundtrack to my nightmare,' she said. 'My ultimate, oh-my-God nightmare.'

'I think I know why.'

She held out the palm of her hand, and he saw tiny droplets settle there. 'It's the music that was playing when it happened, wasn't it?'

'It was.'

'She was singing that same song. I remember now. Before you came in-when you came in-she was singing. She knew all the words. She was dancing around with Ben on her hip.'

Joseph remembered too. Zoe was dancing. Zoe was singing. Zoe was laughing and flushed. What d'you mean, burned the exam scripts? What exam scripts? Hallelujah . . . Hallelujah.

'It was still playing when I called the ambulance,' said Scarlet. 'I think I remember that . . . do I? Yes, I remember. The lady asked me to turn it down.'

Raindrops ran like glass beads along the edge of the awning, gathering in one corner before falling to the steps.

'Her last song,' said Scarlet bleakly. '"Hallelujah".'

Joseph put his arm around her shoulders, and she rested her head against him.

'At least I know what it is now,' she said. 'The nightmare soundtrack. Funny, really. It's just a song. In fact, now I know what it is, I recognise the tune. They used it in Shrek, didn't they, though it sounds a lot different?'

'I think they did.'

He felt her nod. 'That must be why I avoid watching that film. All these years, it's haunted me . . . I couldn't remember the words, couldn't remember the tune; just that deep voice, and how it made me feel. So dark, so cold, so scared . . . Turns out it's just a man, singing a beautiful song. A real-life man.'

'He's real, all right.'

'I used to think it might be the devil himself.'

'Not sure how he'd feel about that. He's Jewish, and he's a Buddhist monk, and a poet. Among a lot of other things.'

Scarlet pondered this. 'I bet he still hasn't got the answer, though. He still doesn't know where they go when they die.' She picked up her mug and sipped absently. Joseph could hear the stream chattering to itself in the black shadows.

'I have to ask you something,' said Scarlet.

'Okay.'

'You have to answer truthfully.'

'Um . . . let's hear the question.'

'Why did you hit her? I mean, what actually made you do it at that particular moment? You'd never done it before, had you?'

'Scarlet. That's . . .' Joseph fumbled for the safest way to answer. 'That doesn't matter.'

'It does to me.'

'Nothing excuses what I did. Nothing could.'

'All the same.' She turned her head to look at him. 'I'd like to know.'

Joseph thought for a time. 'Okay. I'd been marking A-level papers. Mum burned them all on the bonfire. I lost my temper.'

'On the bonfire?'

'Yes.'

A long pause. 'Out by the playhouse?'

'Yes.'

Scarlet's voice had become breathy. 'That day? She'd burned them all that day?'

'Yes-but it doesn't matter. It's irrelevant.'

'It wasn't her that burned them,' said Scarlet. 'It was me and Theo.'

Joseph had been over those last moments a thousand times, as though by some effort of will he might divert the flow of history and give the story some different ending. He'd stood stunned in the garden, staring down at the smoking embers of his marriage. There were still sparks in the cinders, still smouldering twigs. He turned the dying fire with his foot in the vain hope that by some miracle he was wrong; that the scripts were safely parcelled up and waiting in his study, ready for him to mark them and send them off with the courier. His shoe was caked in grey ash. He felt the crackle of paper, stooped, and picked up a forlorn little fragment. It lay charred in his fingers, edged in black, a teenager's anxious exam handwriting: be argued that the fact that there are so many conspiracy theories surrounding the assassination of President Kennedy is a symptom of the paranoia and Joseph felt sickening grief for the young person, whose hopes and dreams and university places rested on this exam.

The pain of months-years-had caught light in that one moment. He'd been caught, spun and dizzied but never lost sight of his love for Zoe, and yet she seemed hell-bent on destroying everything they had. Grief flared and exploded, engulfing Joseph in a fire-red rage.

It was too much. It was too much. He crammed the charred fragment into his pocket. Later, it became an exhibit in the case of Regina v Scott. Then he strode back into the house, deafened by the roar of flames.

Scarlet was speaking hesitantly, as though recounting a half-remembered dream.

'We raked everything into a big heap. Leaves. Branches. Mum got it started with firelighters, and . . . and a massive pile of paper. She said it was the recycling and we had to burn it all because the bin was full. She gave us each a wodge to chuck in. She said we were people from some lost tribe, dancing around our campfire . . . It was fun. We scrumpled our paper and chucked it on. We burned it all. Then we toasted marshmallows.'

'Marshmallows.' Joseph sighed. The rage was long gone. It had flared with searing heat during the three terrible minutes between his leaving the bonfire and Zoe's head hitting the fender. Then it had been doused. Permanently.

'I'm sorry we burned the exams,' said Scarlet.

'Don't be sorry. You didn't know.'

'Dad?' He felt her fingers, warm as they clambered over his cheek. 'Don't cry.'

'I love her,' spluttered Joseph.

'Me too.'

The beck was trying to cheer them up, giggling and gurgling around the stepping stones.

'Do you think she's still here?' asked Scarlet.

'Do you?'

'Um . . .' She turned up her face, as though trying to read something in the blanketed sky. 'No. I think she's gone. I think she left us right then and there, in our sitting room. She isn't coming back. And you know what else I think?'

'What else?'

'I think we'll manage.'

Twenty-eight.

Scarlet Ben and Hannah were making biscuits in the kitchen. I recognised the smell of baking as I arrived home after violin on Monday-a warm butteriness that made my nose crinkle. Ben was wearing his red shorts and kneeling on a chair at the table, using a biscuit cutter to cut out gingerbread men. He was working extremely carefully, pressing down with all his might-until his eyes just about popped-and peeling each man shape off the board. When Hannah wasn't looking, he shoved a bit into his mouth. Then he smiled naughtily at me.

Hannah was standing at the table too, wearing an apron and rolling out the dough for him. She did air kisses and waved floury hands at me. 'Hello there!' she said gaily. 'Cottage industry going on here.'

I stopped to look at a very messy picture on the dresser, obviously one of Ben's from school. Hannah claims he's good at art for an almost five-year-old, but I can't see it myself. He uses gallons of water and oodles of black. The paper gets so wet his brush goes right through it, and his pictures always consist of messy black puddles and black sticks that he swears are people.

This particular picture was different from normal, though, because it actually had some colour. In fact, there were lots of colours and an enormous purple swirl in the middle.

'Hey, Ben,' I said, and whistled. 'Nice.'

'My best ever,' he boasted, doing his chest-puffing thing.

Hannah's rolling suddenly seemed a lot more vigorous. 'Good day at school?' she asked.

'It was okay.'

'Learn anything?'

'Nope.'