By the bed, a pair of fluffy pink mules are waiting for my feet, a lemon nylon négligé hanging on a hook on the door is similarly waiting for my body. Laid across my bed there’s a stocking as heavy as if it still contained a leg. There’s a gift-tag pinned on it and I reach down and turn the tag over so that I can read it. It says, To Isobel from ‘Father Christmas’! What does this mean? Who is ‘Father Christmas’?

Guiltily – for I may not be the ‘Isobel’ of the gift-tag – I investigate the contents of the stocking. Little gifts suitable for a girl – bath cubes and handbag vanity mirrors, hair bands and chocolate drops.

Half-reluctant, half-curious, I get out of bed and slip on the mules and the négligé. There’s a large cheval-mirror in the corner, not a heavy one like Mrs Baxter’s, but a pretty mock Louis-Quinze thing in gilded whitewood. I tread softly on my new carpet in case I’m treading on my dreams (you never know) and look in the mirror. I’m also the same and yet not the same. Some differences are obvious – my hair, for example, is much better tended than usual – but there are subtle changes that are more puzzling. Is it just my madness or do I look, well (how can I say it?), happy? What’s wrong?

On my dressing-table there’s an array of teenage cosmetics – pale pink lipsticks and pearly nail varnish. I open the whitewood wardrobe and find it’s full of nice clothes – shirtwaisters and big dirndl skirts, soft Orlon sweaters in pastel colours, a little jersey suit. This is certainly an infinitely better version of Christmas than the previous three, but I hardly need remind myself that appearances can be deceptive – who knows what lurks beneath this pleasant surface? What kind of teenage Faustian pact have I entered into to bring about this change in my fortunes? Have I given up my eternal soul to Mephistopheles for nice clothes and a date every Saturday night?

From the wardrobe I choose a green linen sack-dress and a white Courtelle cardigan and exchange the fluffy mules for a pair of black kitten-heeled shoes and parade in front of the mirror, pleased with my transformation into a perfectly normal-looking person.

From the window I can see an outside world covered in a glittering white pantomime-frost. Out in the field beyond the garden the Lady Oak looks like a tree from an Arthur Rackham book, a fine-cut black silhouette against the winter sky. Four Christmases in a row and different weather each time. Pretty wondrous strange, if you ask me.

The table is covered in a thick white cloth and the Widow’s silver is out, as well as her flower-sprigged china, all reconstituted from its broken pieces. The Widow’s chrome teapot sits as usual in the middle of the table, clean and polished and wearing a newly knitted cosy in brown and yellow. The Widow herself (‘Surprise!’) is sitting next to Vinny, almost as spruce as her teapot, her grey hair in a tidy bun, her spectacles perched on the edge of her nose. She looks in remarkably good shape for one so old – certainly the Widow looks in very good shape for someone who’s dead … this is, as usual, all very confusing. There’s to be no more dying then?

A hand reaches over the table and takes a piece of toast. I open the door a fraction more to see who the hand belongs to. Gordon. Not the usual careworn Gordon, but a cheerful Gordon, grown slightly plump around the jowls and the waistline as might befit a prosperous grocer. He turns to Charles and says, ‘Sure you don’t want any more bacon, old chap?’ and Charles mumbles through a mouthful of egg, ‘No thanks.’

I could swear that Charles looks taller, but then he is sitting down so I can’t really be sure. He certainly looks less spotty, less miserable, less idiotic. There’s somebody else at the table, sitting next to Gordon, wreathed in cigarette smoke. Gordon turns to this invisible person and pours them another cup of coffee without asking, or being asked. I can see a hand belonging to this person – pale skin and long, thin fingers that end in scarlet nails.

I have to push the door open further to see who this person is – too far, for Gordon looks up and says, ‘Hello, old thing, I thought you were never going to wake up. Come and have some breakfast.’

And the invisible person – who is now visible – says, Darling, come in and sit down. What do you want for breakfast?

I am a radiant being, I rise up and float for happiness, float round the dining-table, past my brother who has grown almost handsome now, past Vinny and the Widow, rest as lightly as a butterfly on the carpet and kiss Eliza on the cheek. Merry Christmas, darling. On her finger, a ring sparkles, emeralds and diamonds catching lights off the fire in the hearth. This is neither past nor future – this, surely, must be my parallel life, the one where everything goes right. The one where real, right justice prevails (the one with no pain). The one that should only exist in fiction.

Gordon brings in the pudding, flaming like a dragon, and the Widow picks up a silver sauce-boat and says, ‘Now – who’s for rum and butter sauce?’

When we’re as stuffed as Christmas geese ourselves we play a quiet hand of rummy in the living-room, to the accompaniment of Christmas carols on a record the Widow brings out. Once we’ve begun to digest our dinner we play a noisy game of Racing Demon and then a hilarious game of Charades at which Eliza proves particularly talented. Someone should go and fetch Mrs Baxter, this is just the kind of Christmas she would love.

It’s dark outside, but inside everything glows with its own inner light – the Widow’s poinsettias, the polished mahogany of the table, the tinsel and Christmas cards, the holly with its red berries, the sprig of mistletoe hanging from the Widow’s chandelier, beneath which Gordon is even at this moment kissing Eliza so fiercely that the Widow can’t resist a little tutting.

Then it’s time for more food, here is the Widow already with a big wooden tray piled high with mince pies and Christmas cake, turkey sandwiches and sticks of celery in the engraved celery glass. We eat sitting round the fire, then Gordon says, ‘Let’s have a sing-song, eh, Vin?’ and we sing lustily, ‘Early One Morning’, ‘Polly-Wolly-Doodle’ and ‘What Shall We Do With the Drunken Sailor?’ to which (miraculously) I find I know all the words.

Then Gordon is prompted to sing ‘Sweet Lass of Richmond Hill’ which he does beautifully and follows it up with ‘Scarlet Ribbons’ which brings tears to Eliza’s eyes. We finish up with ‘One Fish Ball’ and ‘Some Folks Do’ and even Vinny is inclined to cheer the merry, merry heart that laughs by night and day. This is pure wish fulfilment. We are an ideal family. We are a happy family. I am living the perfect plot, but what will the ending be like?

Is this real? Or am I imagining it? And what is the difference? If I imagine a Christmas table groaning under fatted goose and flaming pudding, why isn’t it as real as one that really happened? How is an imagined Christmas different from a remembered one?

We’ve just embarked on another round of mince pies and pot of tea when a car horn hoots outside. Eliza pulls the curtain at the window aside and says (to me), It’s for you, darling, it’s your boyfriend.

My boyfriend – what a wonderful phrase. But who will my boyfriend be? ‘Here’s Malcolm,’ Gordon says, striding towards him and shaking his hand as Vinny lets him in. ‘Happy Christmas, Malcolm!’

‘Happy Christmas, sir,’ Malcolm Lovat says and goes around the room exchanging the season’s greetings with everyone. He blushes when Eliza murmurs, Happy Christmas, darling, and kisses him full on the lips but Gordon laughs and says, ‘You’ll have to excuse my wife, Malcolm, she actually invented flirting, you know. We’re trying to persuade her to take out the patent and make us lots of money!’

Oh, that’s not fair, darling, Eliza says, we were standing under the mistletoe – that’s allowed.

How long can this last? What if it could go on for ever?

‘Of course,’ he grins, ‘she’s one of my parents, after all.’

‘And she’s quite well?’

‘Perfectly.’

Perhaps nobody in the world is dead or dying? Perhaps everybody is alive and well – and happy, I muse, as I follow Malcolm out into the hallway. Perhaps there is no sickness or famine or war. A chorus of Goodbyes! echoes behind us and I pause abruptly on the front doorstep – of course! This is heaven. I have died and gone to heaven. I had died in the car crash – so has Malcolm and we’re in heaven where our families have been waiting for us – but then they’d all be dead too. Has everyone died? Everyone in the whole world? Perhaps this is the Day of Judgment and the unnamed dead, those who the flood did and the fire shall – are risen up and reformed from the dust that they have been.

Isobel?’

‘Yes, yes, I’m coming,’ I reply hastily and pull the front door shut behind me. As I climb into the car I glance back uneasily at the door and its magnificent, ideal, holly wreath – what if I have just shut myself out of heaven? What a ghastly thought. But the engine is running, my handsome boyfriend is waiting for me and so away we go down the drive.

‘I thought’, Malcolm grins (this is a more cheerful and carefree Malcolm than I’ve seen of late. Hardly the same person at all, in fact), ‘that we might go for a little spin first? Get some time on our own.’ Does he mean sex? At the very least he must mean kissing surely?

‘Yes, why not? Sounds like a good idea to me.’ This is a dream, a very good one, and I may as well make the best of it.

‘Mm?’

‘I was thinking, why don’t we get engaged in the New Year? I mean I know I’m still at med school and everything, and I know you’re only sixteen and you want to go to art college – and there’s no way I would stand in your way, I think women should be more than housewives if they want to and would respect any decision you make …’ (This is definitely, without any shadow of a doubt, a dream.)

It starts to snow, great flurries that hit the windscreen as if someone had thrown them from a bucket, like pantomime glitter. Hang on, something’s wrong here. ‘Hang on a minute …’

‘What?’ Malcolm laughs.

‘Are we going to Boscrambe Woods?’

‘I thought so, why not?’

‘You’re Malcolm Lovat!’ I say to him accusingly. He laughs uproariously. ‘Guilty,’ he says, taking his hands off the wheel and holding them above his head.

‘Don’t!’ I yell at him. ‘Don’t do that, we could have an accident. We’re going to have an accident anyway. Don’t you understand? Stop the car!’

‘OK, OK, keep your shirt on.’ He stops laughing and says softly, ‘Izzie, what’s the matter?’ But it’s too late – another car is careering down the hill from Boscrambe Woods, skidding helplessly on the ice. I’m dazzled by the headlights, a dozen suns in my eyes. ‘Christ!’ Malcolm Lovat cries and pushes me over to the car door, trying to cover me with his body, trying to push me out, but it’s too late and the other car hits us with an explosive bang, followed by an infernal shrieking and grinding of metal as it shoves us along, off the road and down an embankment.

An avalanche of white snow seems to envelop the car and we’re plunged into a white world of silence, the silence of absolute deafness. I am doomed to relive this experience again and again, each time the details are different, but the ending is always the same.

Perhaps this is an ordeal I have been set – perhaps I am Janet to Malcolm Lovat’s Tam Lin. Perhaps the Queen of Elfland – instead of turning him into a snake in my arms, or a lion or a red hot bar of iron – is trying to wrest away her human tithe from me by constantly killing him. Again and again.

But it’s no enchantment. Flights of invisible angels crowd the car-crash scene waiting impatiently. Malcolm Lovat’s skin is as white as the snow, his lips as blue as ice. They open slowly, an ice hole from which emerges the only words possible. Tears are streaming down my cheeks, freezing as they leave my eyes, hanging on my cheeks like chandelier drops. ‘Help me,’ he says, refusing to be silent. ‘Help me.’ But I am helpless to help, this story must always, always, end badly.

A pair of warm lips cover my own icy ones. Someone begins to kiss me, but then I’m washed over by the cold, cold wave and dragged down, under the thick-ribbed ice and into the watery world below. Here is an iceberg as big as a cathedral, here are the long-dead bones of ships crushed by pack-ice. Shoals of silver fish shimmer and flicker and whales like great stately barques pass overhead as black shadows.

I pop up suddenly, like a cork through a hole in the ice. In the arctic world above it is snowing, the grey sky is full of snow. Mother Carey’s chickens flock overhead, polar bears pad softly on the ice, but I don’t stop, I carry on rising upwards, flying over the ice-cap on the top of the world, higher and higher, set free of gravity, set free of everything.

I am circling the globe of the world, I am visiting the round earth’s imagined corners, the ice-locked northern wastes, the Lithuanian Forests, the great Tibetan Plateau, the cold deserts of Asia and the hot deserts of Arabia, lifted on thermals above the steaming jungles of Africa, skimming above the South China Seas like a flying fish, skating the endless Pacific blue that floods the southern hemisphere, racing the sunset to the Bermudas, down the spine of the Andes, down to the bottom of the world, and more ice, ice so clean and blue that it must have been frozen at the beginning of time when everything was new.

But I am leaving the earth, higher still, up into the inkiness of night, leaving the earth spinning down below, a blue and green ball. Now I am a new constellation in the night sky, spread across the northern hemisphere, Sagittarius on my left shoulder, Scorpio rising on my right – the metamorphosis of yet another hapless girl into something rich and strange. Blessed Isobel full of light, as bright as a million diamonds, soon I will turn into a supernova and explode in glittering fragments and spread to the edges of the universe. I am as full of ecstasy as an archangel – I am my true self. For a long time …

The only path I will find will be the one that leads deeper and deeper into the wilderness of fear. I lie down at the foot of a tree and close my eyes. Leaves drift down and cover my face. Small animals scrabble, digging up the soil and burying me, hiding me from the terror of the wood. I cannot open my eyes, my eyelids are the lead lids of coffins, soldered shut, I am buried in the deep in the cold ground, earth stops up my nostrils, gathers in my ears, my mouth is full of sour soil.

My head hurts. My head feels as if someone’s blown it up with a bicycle pump. It throbs dangerously, someone has cut the top off my skull and scooped out my brains and replaced them with a bag of tangled and frayed nerves, but I can’t tell anyone because I have been robbed of the power of speech. I don’t want to be in this metallic world of pain, I want to go back to the cold Antarctic and play with the mermaid seals.

But where is he?

I know this other patient from somewhere. I hear her voice, strange and hypnotic, weaving its way through the white cotton wool that they’ve wrapped my glass body in. Her voice fills in the intervals between nurses and consultant’s rounds, visitors and sleep. After days, possibly weeks, maybe years, I realize that she’s telling me a story. She is my own Scheherazade, she knows everything, she must be the storyteller from the end of the world. But how does it begin? Why it begins, as it must, she says, with the arrival of the baby –