Out of the corner of my eye I catch a glimpse of something on my bedside table – the gift-wrapped box of Bronnley soaps. I sit up and release them from their wrapping-paper. From somewhere down below I can hear the sound of the radio playing carols and the baby crying. Thoughtfully I hold one of the soap lemons in my hand where it sits heavily like a sour little moon. Angels and ministers of grace defend us and help me Boab.

If yesterday was Christmas Eve then today should be Christmas Day – but of course I know that the laws of causality are as bent as time’s arrow and I am not the person to be trying to make predictions about sequential events.

Perhaps there really is no permanent reality, only the reality of change. A disturbing kind of thought.

On cue, Charles comes bursting into my room and says, ‘Have you got any wrapping-paper? I’ve only got one present left to wrap and I’ve run out.’

‘What day do you think it is?’ I ask, and he looks at me as if I’m mad (well, I am). ‘It’s Christmas Eve, of course. What day do you think it is?’ (Can time be this relative?)

This is ridiculous. I put my head under the covers. Have I actually succeeded in calling back yesterday? Have I stepped in the same river twice? Is the whole dreadful day going to happen again? Isn’t it enough to have had the nightmare once without repeating it? How many rhetorical questions can I ask myself without getting bored?

Maybe I’ve died and gone to hell and this is my punishment – to live the worst day of my life over and over again for eternity.

Perhaps I’m dreaming my life. Perhaps I’ll wake up and find I’m a butterfly. Or a caterpillar. Or a mushroom, a mushroom dreaming it’s a girl called Isobel Fairfax.

Do I still have free will – maybe if I just stay in bed – not go to the Walshes’ party, certainly not go driving anywhere with Malcolm Lovat – then everyone will be safe. I close my eyes and try and force myself back to sleep (perhaps this is what cats are doing – sleeping to try and make things disappear. Dogs maybe), but I’ve murdered sleep as soundly as I’ve destroyed the laws of time.

But what if, I suddenly think, opening my eyes and staring at the pink dress, what if it isn’t my malign influence that precipitated (or precipitates, or will precipitate – take your pick) events? What if they’re going to happen anyway? And if they’re going to happen anyway then maybe there’s something I can do to stop them. And then, even if Malcolm and Hilary and Richard still die, at least it won’t be my fault. Which is something.

But there again – for all I know they’re dead already. I drag myself out of bed, like it or not, I’m going to have to find out what’s going on. I lift up the skirt of the pink dress, yes, there is the petticoat, intact and in place. I give a weary sigh.

There’s no-one about downstairs – Vinny, Debbie and Gordon are not at their previous stations, although the mince pies know their place in the plot, piled high ready on the kitchen table, nicely dusted with icing-sugar like snow. I eat one, then another, then a third – I’m ravenous. I haven’t had anything to eat since last night’s stale custard creams, although, of course, it’s possible that I haven’t actually eaten them yet. Reality’s slipping away from me faster than I can think about it.

I phone the Lovats. Malcolm answers. ‘Hello? Hello?’ he keeps repeating until I put the phone down because I can’t think of anything to say that won’t sound insane. I try the Walshes next and Mrs Walsh’s flutey tones penetrate my eardrum. I mumble something about Hilary and Mrs Walsh says she’s gone into town with Dorothy.

I decide not to check on the Primrose household, I don’t really care whether Richard’s dead or not and two out of three isn’t bad going. But how to keep them alive, that’s the question. The kind of question that Charles could get his teeth into but there’s no sign of him either. Arden’s like the Marie Celeste, the only survivor of whatever invisible disaster has occurred is the baby (it’s indestructible) which is in its pram in the hall wearing its lungs out.

I take it (I can’t bring myself to call it Jodi) out of its pram and try and soothe it but it’s in a terrible rage, screaming its head off (well, not quite), every so often its body going rigid and stiff as if it’s having a fit. Its face is red with anger and its little fists are bunched up furiously as if it would like to punch somebody.

I try and wrap it in its shawl but it’s too awkward so in the end I just kind of bundle it up like a cabbage and carry it round to Sithean. Maybe Mrs Baxter will be able to do something with it. And anyway I’d like to talk to somebody about what’s happening to me, and preferably someone I didn’t help to kill yesterday.

There’s an eerie feeling of abandonment in the Baxter household as well. Sithean seems as empty and deserted as Arden. There’s no answer when I shout ‘Hello!’ to the empty air, the only sound the sobs and hiccups of the baby.

In the living-room a fire is blazing in the hearth and the Christmas tree lights blink on and off, but whether they’re supposed to do that or it’s due to my electrical interference I can’t say.

In the dining-room, the table’s been set with the best china and plates. Mrs Baxter makes almost as much fuss about Christmas Eve as she does about Christmas Day. If it was up to Mrs Baxter she would probably celebrate Christmas every day of the year.

In the middle of the table there are red candles and each place setting has a cracker and a Christmas paper napkin – red with green holly leaves – twirled into a fanciful shape. A prawn cocktail in a wineglass sits on each plate, ready to be eaten.

I sit down on one of the chairs and pull a lettuce leaf from the prawn cocktail and nibble at it while I try to figure out where everyone’s gone. Perhaps the Baxters have taken to slipping down wormholes in time as well. Perhaps the Baxters are at this moment celebrating Christmas in the eighteenth century or the Dark Ages. I smear some of the pink-coloured salad cream from the prawn cocktail on to the baby’s lips and it’s shocked into silence.

Without meaning to, I find I’ve finished the prawn cocktail. Perhaps if I go round the table and eat the other two it would look better, then I could pretend there were never any to begin with. But too late – the back door slams and Mr Baxter marches down the hall, glimpses me through the open dining-room door, marches on and then doubles back and snaps at me, ‘What are you doing here? Sitting in my place? Eating my meal?’

‘Where’s Audrey and Mrs Baxter?’ I ask, jumping up from the table guiltily.

‘What an interesting question,’ he says in the voice he reserves for the pupils he considers to be the greatest idiots. His eyes are bulging with madness. ‘I mean where are they?’ he says, enunciating each word carefully. ‘Hmm, let me see …’ He makes a face of mock-puzzlement and looks down one end of a cracker. ‘No,’ he says, ‘they’re not in there.’ (How tedious it must be to live with Mr Baxter.) This pantomime goes on for some time until the volume of noise from the baby (it has its uses) drives him from the room and he goes up to his study.

I carry the baby through to the living-room and sit on the sofa with it. The blinking lights on the Christmas tree make the baby quite peaceable. It’s stuck its fist in its mouth as if to force itself to be quiet and my heart goes out to it. It’s got all its life ahead of it to be unhappy in, it seems a shame it has to start so soon.

The back door opens and closes. I hope this is Mrs Baxter and Audrey and not Mr Baxter coming in the house for a second time without having gone out first (you become paranoid pretty quickly once time starts breaking down, or breaking up. Or whatever).

But thankfully it is Mrs Baxter and Audrey. They’re wearing their outdoor clothes – coats and scarves and woollen hats – as if they’ve just been out for a walk. ‘We’ve just been out for a wee walk,’ Mrs Baxter says, ‘to give Daddy a chance to calm down. He was in a bit of a stushie with himself,’ she adds with a rueful little smile. She looks incredibly miserable.

At the sight of the baby Mrs Baxter goes into maternal meltdown and sends Audrey to look for its present under the tree. Audrey unwraps the baby’s present – a rattle (as if it doesn’t make enough noise already) – and gives it to the baby with a lovely smile. ‘I’ll put the kettle on,’ Mrs Baxter says. ‘You’ll have a cuppie, won’t you, Isobel?’

‘Daddy,’ Audrey says when Mrs Baxter’s left the room, and then stops, apparently incapable of saying anything else. ‘Is in a bit of a stushie?’ I prompt helpfully. She takes the baby and cradles it protectively, resting her chin on the top of its red-gold floss. Her eyes fill up with tears and she makes a tremendous effort to stop them spilling over on to the baby. ‘Boys,’ she manages to say.

‘Boys? He thinks you’ve …?’

‘He’s convinced I’ve been with a boy,’ she whispers.

‘And have you?’ (She must have surely, how else can we account for the phenomenon of baby Jodi? Although if anyone’s a candidate for immaculate conception then it’s Audrey.)

She looks at me with her big pained eyes as if I’ve just asked the most ridiculous question and holds the baby closer. It’s quietened down now, has fallen asleep in fact, its fist still jammed in its mouth, perhaps in case it’s tempted to blurt out the truth in its sleep. They look like the perfect nativity scene, Audrey with her lovely Mother-of-God kind of smile and the baby sleeping happily in her arms. Cautiously, with one hand, Audrey unbuttons her coat, unwinds her scarf, puts her hand up to her head and takes off her woollen hat – but instead of shaking down her lovely Mother-of-God kind of hair there’s nothing there. I gasp in horror at her shorn head, not the urchin cut of a hairdresser but the ragged shearing of a wartime collaborator. ‘Daddy,’ Audrey says.

Mrs Baxter returns with a tray piled high with Christmas baking and tries not to look at the results of ‘Daddy’s’ stushie on Audrey’s head. She’s about to say something when we hear Mr Baxter pounding back down the stairs and we listen to his footfall as if we’re in a horror film awaiting the entrance of some unknown monster and it’s almost a relief to see he’s still human when he comes barging in the room and scowls at me and says, ‘Still here? You’re a bad influence. I expect it’s you who’s been leading Audrey here astray, isn’t it?’

‘Daddy, don’t,’ Mrs Baxter says in her most cajoling voice.

‘And you can shut your face,’ he says in response. He puts his own face a few inches away from mine, a bully’s stance, and says, ‘Well, Isobel, who’s Audrey been messing about with? Some boy’s had her, who is it? Not that ugly little brother of yours, I hope.’

‘Daddy, don’t,’ Audrey pleads.

‘You shut up, you little whore,’ Mr Baxter bellows, rounding on her, ‘giving yourself to boys, letting them do God knows what to you! Who was it? Tell me!’ Mrs Baxter’s jigging on the spot, flapping her hands as if she’s trying to learn how to fly. Mr Baxter takes something from the pocket of his tweed jacket and starts waving it around. Something dark and metallic and gun-shaped. A gun, in fact.

‘Your old service revolver,’ Mrs Baxter marvels. ‘I thought you got rid of that years ago, Daddy.’ Mr Baxter puts the gun down on the mantelpiece with all the Grand Guignol exaggeration of a pantomime villain – the same way, in fact, that he used to put his cane on his desk – so that his pupils’ minds would all focus on it. (I suppose we were lucky he never brought the gun in as a classroom deterrent.)

Then he makes a move towards Audrey, grabbing her by the remains of her hair, pulling her in towards him and roaring at her, ‘Who?’ heedless of the baby which is screaming in terror. More to try and calm the baby down than to appease her father, Audrey finally answers his question and, in a very small voice, says, ‘But, Daddy, it was you.’

I lunge at Mr Baxter to try and make him let go of Audrey without digesting what Audrey’s just said to him. The next thing I know – WALLOP – Mr Baxter turns and punches me in the face. The blow lands square on my cheekbone, a prizefighter punch, the kind that splinters bones and causes brain damage.

I drop to my knees in agony, trying to cradle my entire head while fighting for air. I feel incredibly sick as if I’ve just been dropped from a great height.

Slowly, I grow aware of a strange silence in the room. We all appear to have been paralysed, as if time has actually stopped. I imagine us frozen in this tableau for ever, but just then, Mrs Baxter’s cat, which has been disguising itself as a brindled antimacassar on the back of a Parker Knoll chair, suddenly rolls over and falls off, thudding heavily on its feet on the carpet, then the fire crackles noisily and a lump of coal falls out sizzling on the hearth and everybody wakes up.

Mrs Baxter murmurs, ‘Daddy?’ as if someone’s just told her the improbable answer to a question she’s long puzzled over. Then there’s a little intake of breath from Mrs Baxter that makes me turn and look at her. She’s staring, dumbfounded, at Audrey and the baby. It is obvious when you see them together, I suppose – they actually look quite alike, not just the hair and the small features, but the whey-faced expression of misery they both tend to wear. ‘Audrey?’ Mrs Baxter whispers as big teardrops roll down Audrey’s cheeks. Audrey really should have put on her catskin coat and fled as far as she could from Mr Baxter before we got to this dreadful state of affairs.

Mr Baxter meanwhile walks calmly over to the fireplace, takes his pipe off the mantelpiece and knocks the ash out of it on the hearth as if nothing has happened. I watch as if in a trance as he re-lights his pipe, sucking hard on the stem so that the tiny volcanic glow in the bowl heats and cools, over and over again, until Mr Baxter’s encircled in a faint blue haze. How can he be so calm in the face of so much domestic mayhem? But then I expect that Bluebeard probably locked up his secret butchery and went and made himself a cup of tea afterwards.

I grow suddenly aware of Mrs Baxter in the doorway, standing perfectly still, like a statue. She must have left the room and come back in again because in her hand she’s holding a carving-knife.

I have actually managed to find a scenario worse than yesterday’s! Christmas in Sithean is like being trapped in a nightmarish game of Cluedo – is it Mrs Baxter in the hallway with the carving-knife, or Mr Baxter in the living-room with a gun? Next it’ll be Audrey in the kitchen with the candlestick.

Then Mrs Baxter starts to lumber towards Mr Baxter, in a kind of slow motion, a charging rhinoceros chugging resolutely towards its target. As she charges Mr Baxter, Mrs Baxter makes a dreadful noise, like the moaning wail of an animal in pain. ‘What the hell are you doing, Moira?’ Mr Baxter says irritably, but as Mrs Baxter continues to charge his expression changes to one of disbelief. He looks round, perhaps for his gun, but it’s too late – Mrs Baxter has met her target, slamming into Mr Baxter (who makes a kind of whumph noise), sending him slumped to his knees on the hearthrug, so that for all the world he looks as if he’s suddenly decided to worship Mrs Baxter.

His hands, clutching his stomach, are bright red. Not the red of holly berries. Not the red of poinsettias. Not the red of robins’ breasts nor the red of tomato ketchup. The red of blood. The blood is oozing through Mr Baxter’s fingers, the stain spreading across the front of his Fair Isle pullover, knitted by Mrs Baxter for his last birthday. Last in all senses of the word.

Mrs Baxter, standing over him, bloody knife in hand, is like some terrible figure from Greek tragedy, her face smeared with blood from her first kill. Mr Baxter looks up at Mrs Baxter in astonishment, then looks down at his stomach with equal astonishment. Experimentally, he takes one of his hands away and blood spurts in a thin red fountain, a little gusher so powerful that it sprays the wall.

I snatch a cushion from the sofa and push it up against the source of the blood fountain but almost as soon as I touch him he falls forward on to his face. I try to push him the right way up but he’s too heavy. His eyes are nearly closed and his breathing harsh and shallow. And then suddenly there’s no breathing at all. His eyes stare lifelessly at the carpet. Mrs Baxter has turned back into a statue. Audrey is sitting on the sofa smiling at the baby as if nothing has happened. Who is the maddest person in this room? Mr Baxter is certainly the deadest.

‘But how can that possibly be?’ Eunice puzzles, looking at Audrey and the baby. ‘He’s her father, he can’t be the father of her baby as well.’ There are some things it seems that Eunice doesn’t know. Carmen explains incest and abuse to her in a way that’s remarkably lucid for a girl whose head is full of cheese.

I suppose it must cross all our minds at some point that we could call the police but if it does we never voice the idea. Not even Eunice.

‘Perhaps we should all stick the knife in,’ I suggest miserably, ‘then we’d all be guilty.’

‘Then we’d all go down for murder,’ Eunice points out sensibly.

The three of us sit for quite some time discussing what to do (Audrey and Mrs Baxter are good for nothing). Carmen proposes that we take Mr Baxter to the casualty department of Glebelands General and say that he fell on the knife.

‘While carving the turkey?’ Eunice snorts with derision. If he’d been smaller we could have dragged him over to the hearth and immolated him on the fire. ‘And say what?’ Eunice says sarcastically. ‘That he fell down the chimney when he was delivering the presents?’

I get up and switch the Christmas tree lights off, their winking and blinking is driving me crazy. Carmen shares cigarettes and in the extremity of the situation smokes two at once. ‘I think we should bury him,’ she suggests.

‘Bury him?’ I repeat in horror. Part of me is still waiting for Mr Baxter to get up off the floor and burial seems a bit of a final option.

Carmen passes round a packet of fruit gums. ‘For God’s sake, Carmen,’ Eunice says crossly. ‘But bury him where?’

Carmen continues, warming to the subject now. ‘We could get Mr Baxter’s car, and we could take him somewhere, tip him in the river or bury him in a wood or somewhere.’

‘But none of us can drive,’ I point out.

‘We could have a go,’ Carmen says, always game for anything, ‘or we could just bury him in the garden, that would be easier.’

‘Easier?’ I query doubtfully. ‘And what would we tell people? I mean, how would we explain where he’d gone? People don’t just disappear.’ (What am I saying?) Carmen eats her way through a mince pie with an appetite that does her credit.

By now the rain is lashing against the curtained windows of the living-room (now more of a dead-room really). ‘Right then,’ Eunice says suddenly and proceeds to come over all Girl Guidish, ‘we’re going to need gloves, a torch, some rope and –’ She pauses, her clicking brain momentarily overcome by the circumstances it finds itself in.

‘A spade?’ I offer.

‘A spade, exactly!’

Without replying, we set about dragging Mr Baxter out through the French windows. Carmen, who at some point in her life must have witnessed undertakers in action, smiles sympathetically at the newly created widow and says, ‘It’s time to take Mr Baxter away now, Mrs Baxter.’ Eunice and I exchange uneasy glances, worried that Mrs Baxter might spring up from the sofa and suddenly understand what’s going on, but all she does is smile and say, ‘On you go then.’ A real Mrs Eerie-Cheerie.

We drag Mr Baxter’s lifeless shape out into the rain and along the garden path. Finally, with a lot of grunting and shoving and swearing, we tip him into his grave.

Eunice shines the torch on him. He looks less dead than he did two hours ago. ‘We have to cover his face,’ I say hastily as Carmen picks up her spade again. I run back into the house and snatch a handful of the festive paper napkins from the kitchen and then run back down the path with them and kneel at the side of the hole and put them on his face. ‘Careful,’ Carmen says, worried that I’m about to fall on top of Mr Baxter.

Covering him with soil is easy but disposing of the soil displaced by Mr Baxter is a grim job, trundling awkward wheelbarrows of the heavy wet stuff down to the bottom of the garden where we make a pile of it, like a dark sandcastle.

By the time we straggle back inside we look like we’ve just mined our way down under and back, filthy and soaked to the bone and speechless with shock. We take our shoes off outside the back door and stand under the porch light staring in horror at each other.

Meanwhile, in the kitchen, Mrs Baxter’s making a pot of tea and laying out more Christmas cake and mince pies on plates with festive doilies and the paper napkins which are now doubling as grave-clothes.

Mrs Baxter shoos us into the living-room with the tea-tray, then, putting it down on the coffee table, she beams at us. ‘Come on, come on, help yourselves.’ My heart sinks. ‘And you, Isobel, come on, eat up!’ she urges, handing me a paper napkin, the sight of whose red and green makes me blench. The pain in my face where Mr Baxter hit me is growing more acute by the minute.

There’s blood everywhere in the living-room, streaked on the walls, on the sofa, and the huge bloodstain that has become a macabre figure in the carpet. ‘We’ll have to do something about that,’ Carmen says to me.

‘Dearie me,’ Mrs Baxter says, overhearing this conversation, ‘we’ll need to hire a Bex Bissell for that.’ I’m sure the smell of blood – salt and rust – has seeped into the very air itself. ‘Have a piece of shortie,’ Mrs Baxter urges, ‘I made it myself.’

Audrey stirs, opening her eyes sleepily and spying the baby in her arms smiles her lovely smile. It would take a crowbar to separate them now.

Eunice sighs and leaves the room, coming back with a bucket of hot water and a bottle of Stardrops and mutters, ‘Come on,’ rather viciously at me but I’ve reached a stage of weariness that’s beyond anything. All my bones are sore and if there wasn’t so much blood in the living-room I would curl up on the sofa with Mrs Baxter and fall asleep. ‘It’s nice to have so many young people in the house,’ Mrs Baxter says gaily. ‘Daddy will be so pleased when he gets back – he’s a great one for the young people.’

A statement wrong on so many counts that I forget about the mud and the blood and the horror and sit heavily down on the sofa with my head in my hands.

‘Don’t be bothering yourself with that just now,’ Mrs Baxter says to Eunice, who’s on her knees scrubbing the carpet with an expression on her face that defies description. ‘How about a game of something?’ Mrs Baxter says brightly. ‘How about Rhubarb Charades or Hot Potato? Get Home Safe, Mother – that’s a nice quiet game. Human Croquet, that’s a wonderful game – of course we need more people for that,’ she adds wistfully. (How many people do you need for Human Croquet, for heaven’s sake?)

I stand up suddenly and run to the kitchen and am sick in the sink. The kitchen door’s still wide open, letting the rain in. Our muddy shoes are lined up neatly on the doorstep, like reminders of our lost innocence. I can’t go back into that hellish living-room. I step over the shoes, into the dark unquiet garden and go home.

‘It’s Christmas Day, of course.’

‘How long have I been asleep for?’

‘What on earth are you talking about?’ She moves a sauce-boat a fraction of an inch.

‘Have I eaten Christmas dinner, for example?’

‘For example?’ Debbie frowns. ‘Well, you’ve certainly eaten Christmas dinner. It wasn’t much of an example.’

‘Wish?’ Gordon asks, coming into the kitchen and picking up the arc of wishbone and proffering it to me. I decline.

I have to go round to the Baxters’, I have to find out if Mr Baxter’s alive like Hilary and Richard (presumably) or whether he’s at this moment turning into a vegetable. I run out of the back door and down the drive, the wind whipping through my hair and the rain soaking through my nightdress.

I’m running so fast that I can’t stop at the end of the driveway and run straight into the normally deserted road. The oncoming car’s on top of me before I even register that the dazzling light is coming from its headlights. Our paths are destined to cross exactly in the middle of the road, the driver must have a good view of my terrified face as I bounce on the bonnet before he swerves violently and goes crashing through the hawthorn hedge on the opposite side of the road and drives his car smack into a gnarled old hawthorn tree.

I have certainly seen his face, seen the horror on the features of Malcolm Lovat as he tries to avoid my unavoidable body.

I’ve landed half in the hedge and its thorns have torn at my face and hands. I crawl over to the car. The driver’s door is hanging open and Malcolm is slumped in the seat. I kneel on the ground next to him and put my hand up to hold his. I know there’s no escaping the dreadful words he’s going to say to me. I wait patiently, almost peacefully, for them.

He half-opens his eyes. His hair’s matted with blood, his face almost unrecognizable. ‘Help me,’ he whispers, ‘help me,’ and closes his eyes. I crawl away, back to my hedge, I really can’t bear this.

A policeman suddenly catches sight of me and an ambulanceman rushes over to me with a blanket but I am already gone, washed over by the wave of blackness that takes me down to the bottom of a Polar Ocean where everything is the colour of blue diamonds and only the seals and the mermaids swim.