‘You’ve called the police?’

‘Not yet, Doctor.’ A look of embarrassment crossed the Mother Superior’s face. ‘When Christina left she told one of the orderlies that she was going to "the ball". I’m told that the only ball being held tonight is Prince Rainier’s grand gala in Monaco in honour of President Giscard d’Estaing. I assume that she has gone there, perhaps confusing Prince Rainier with the Prince Charming of her fairy tale, and hoping that he will rescue her. It would be profoundly awkward for the Hospice if she were to create a scene, or even try to..

‘Kill the President? Or the Rainiers? I doubt it.’ Already an idea was forming in my mind. ‘However, to be on the safe side I’ll leave for Monaco immediately. With luck I’ll be there before she can cause any harm to herself.’

Pursued by the Mother Superior’s blessings, I returned to my car and set off into the night. Needless to say, I did not intend to make the journey to Monaco. I was quite certain that I knew where Christina Brossard had fled — to her father’s mansion above Vence.

As I followed the mountain road I reflected on the evidence that had come together — the fantasy of being a skivvy, the all-promising woman psychiatrist, the hallucinogenic drug. The entire fairy tale of Cinderella was being enacted, perhaps unconsciously, by this deranged heiress. If she herself was Cinderella, Dr Valentina Gabor was the fairy godmother, and her magic wand the hypodermic syringe she waved about so spectacularly. The role of the pumpkin was played by the ‘sacred mushroom’, the hallucinogenic fungus from which psilocybin was extracted. Under its influence even an ancient laundry van would seem like a golden coach. And as for the ‘ball’, this of course was the whole psychedelic trip.

But who then was Prince Charming? As I arrived at the great mansion at the end of its drive it occurred to me that I might be unwittingly casting myself in the role, fulfilling a fantasy demanded by this unhappy girl. Holding tight to my medical case, I walked across the dark gravel to the open entrance, where the laundry van had ended its journey in the centre of a flower-bed.

High above, in one of the great rooms facing the sea, a light flickered, as if something was being burned in a grate. I paused in the hall to let my eyes feel their way in the darkness, wondering how best to approach this distraught young woman. Then I saw that the massive Venetian clock above the staircase had been savagely mutilated. Several of the ornate numerals tilted on their mountings. The hands had stopped at midnight, and someone had tried to wrench them from the face.

For all my resistance to that pseudo-science, it occurred to me that once again a psychoanalytic explanation made complete sense of these bizarre events and the fable of Cinderella that underpinned them. I walked up the staircase past the dismembered clock. Despite the fear-crazed assault on them, the erect hands still stood upright on the midnight hour — that time when the ball ended, when the courtships and frivolities of the party were over and the serious business of a real sexual relationship began. Fearful of that male erection, Cinderella always fled at midnight.

But what had Christina Brossard fled from in this Palladian mansion?

Suppose that the Prince Charming who courted her so dangerously but so appealingly were in fact her own father. Had some kind of incestuous act involved the widowed industrialist and his adolescent daughter, herself an uncanny image of his dead wife? His revulsion and self-disgust at having committed incest would explain his apparently motiveless suicide and his daughter’s guilt — as I knew only too well from my court attendances as an expert medical witness, far from hating the fathers who forced them to commit incest, daughters were invariably plagued by powerful feelings of guilt at their responsibility for their parent’s imprisonment. So after his death she would naturally return to the house, and try to expiate that guilt as a servant-girl. And what better model for an heiress than Cinderella herself?

Drawn by the distant flames, I crossed the upstairs hallway and entered the great bedroom. It was filled with paintings of young nudes cavorting with centaurs, unmistakably Gaston Brossard’s master-bedroom, perhaps where the act of incest had taken place.

Flames lifted from the fireplace, illuminating the ash-streaked face of Christina. She knelt by the grate, crooning as she fed the last of the pages torn from a familiar book of fairy tales. Head to one side, she stared at the soft blaze with overlit eyes, stroking the rough seams of the hospital tunic she wore over her bare legs.

I guessed that she was in the middle of her hallucination and that she saw herself in a resplendent gown. Yet her drifting eyes looked up at me with an expression of almost knowing calm, as if she recognized me and was waiting for me to play my role in the fable and bring it to its proper conclusion. I thought of the mutilated hands of the clock above the staircase. All that remained was to restore the glass slipper to its rightful owner.

Had I now to play the part of her rescuer? Remembering the familiar sexual symbolism of the foot, I knew that the glass slipper was nothing more than a transparent and therefore guilt-free vagina. And as for the foot to be placed within it, of course this would not be her own but that of her true lover, the erect male sexual organ from which she fled.

Reaching forward, she added the cover of the fairy tale to the dying blaze, and then looked up at me with waiting eyes. For a moment I hesitated. High on psilocybin, she would be unable to distinguish truth from fantasy, so I could play out my role and bring this psychoanalytic drama to its conclusion without any fear of professional disapproval. My action would not take place in the real world, but within that imaginary realm where the fable of Cinderella was being enacted.

Knowing my role now, and the object which I myself had to place in that glass slipper, I took her hands and drew her from her knees towards her father’s bed.

I murmured: ‘Cinderella..

But wait — they’re about to leave the terrace. You can look at them now, everyone else is staring frankly at this attractive young woman and her decrepit companion. Sitting here in the centre of Monte Carlo on this magnificent spring day, it’s hard to believe that these strange events ever occurred.

It’s almost unnerving — she’s looking straight at me. But does she recognise me, the dermatologist who freed her from her obsession and restored her to health?

Her companion, sadly, was the only casualty of this radical therapy. As he sits hunched at his table, fumbling with himself like an old man, I can tell you that he was once a fashionable physician whom she met just before her release from the Hospice. They were married three months later, but the marriage was hardly a success. By whatever means, presumably certain methods of her own, she transformed him into this old man.

But why? Simply, that in order to make the incest fantasy credible, any man she marries, however young and princely, however charming, must become old enough to be her father.

Wait! She is coming towards this table. Perhaps she needs my help? She stands in front of the restaurant mirror looking at herself and her elderly husband, and places a hand on his shoulder.

That elegant face with its knowing smile. Let me try to shake that composure, and whisper the title of this cheap magazine on my lap.

‘CINDERELLA…’

Her hand pats my shoulder indulgently.

‘Father, it’s time to go back to the Hospice. I promised the Mother Superior that I wouldn’t over-tire you.’

Knowing, elegant and completely self-possessed.

‘And do stop playing that game with yourself. You know it only excites you.’