I dropped to one knee, applied an eye to the keyhole and saw the back of the painted chair wedged against the door. ‘Felix, Lucas…’ I wished I sounded more certain, more like a parent in control.

For all the response I got, I might as well have been in outer space. The twins were out of sight but there were cautious flurries of movement. The carpet pile pressed into my knee and my toes cramped, as they always did in that position.

In that position I was a fool. In that position the twins had the upper hand.

As I got to my feet, a piece of paper shot under the door: ‘Go away, Mumy’ in green crayon.

I leant against the wall, and crumpled slowly, wearily, to a sitting position. The misspelt ‘Mumy’ was clear, accusatory and reproaching. It cut like a knife.

This was usually the moment when I demanded, ‘Nathan, will you please sort this one out. The twins are naughty/revolting/obstinate/crying…’ Looking back, I had issued the challenge to him more often than I cared to admit now. And, imperfectly concealing his pleasure at my SOS for a firefighter, Nathan would slouch into the fray: ‘You all need your heads knocking together. Just be firm.’ He had been fond of saying ‘Take no nonsense. Let them know who’s leader of the pack.’ Occasionally, I teased him for being pompous and – sometimes – I cried because I couldn’t get the hang of family life. Here was the continuing conundrum. How on earth had an intelligent, capable woman like me got into such a muddle?

I looked up, fully expecting to hear Nathan’s tread on the stairs, the hand on my shoulder, his voice in my ear. Then I heard myself murmur aloud, ‘Nathan will never have really grey hair.’

But all that lay in the past.

Go away, Mumy.

At Claire Manor, I resorted to a sleeping pill and woke in an unfamiliar bed artfully draped in muslin à la Polonaise. Across the room, the curtains fell expensively to the floor and the cushion on the chair sported antique-style tassels.

It was the kind of room that was featured in magazines. It exuded discreet affluence and comfort, an exemplar of the bargain struck between fantasy and reality. No one could, or would, ever live in it.

Luxuriously and beautifully run as it was, Claire Manor was not an innocent place. In fact, its raison d’être was knowingness. In the bathrooms there was a battery of potions and creams, which guests were invited to secrete in their luggage. If we used them, they wooed enticingly, dewy skin and renewed collagen were ours. They posed an interesting dilemma. There was no chance that they could deliver what they promised, but if the situation was left to Nature there was absolutely no chance of achieving them either. A selection of books ranged on a shelf – The Insightful Soul, Ten Steps to a Beautiful Body, Yoga for the Spirit and Managing Ourselves - added to the cool, considered conspiracy.

Across the corridor, which was covered with deep-pile carpet, Gisela occupied a room identical to mine – except that it was larger, had a complimentary fruit bowl and the bathroom was draped with more towels.

No child ever set foot in Claire Manor. None would be permitted to invade its pink, scented, draped and hushed interiors.

I stretched out to experiment with toe aerobics, and tried to recapture the uplift of spirits I had experienced when Gisela and I arrived in Reception. ‘I can run amok,’ I confided to Gisela. ‘Eat pickled onions and order a BLT on Room Service at four in the morning.’

She had looked at me oddly. ‘Minty, this is a health farm. May I remind you that your body is a temple?’

In the cold light of morning, groggy with the sleeping pill, an all-too-vivid mental picture took shape. I knew that Lucas and Felix would be sitting up in bed and saying to Eve, ‘Mummy’s gone too.’

As we ate dinner (mung beans and onion ragoût), Roger phoned Gisela twice for no good reason. Gisela listened, soothed, then apologized for the intrusion. ‘Roger gets agitated when I go away. He hates it.’ She poked at a bean. ‘This is a man who has run a couple of large companies and made millions…’

‘And?’ I prompted when she fell silent.

Gisela grasped her water glass. ‘That’s what I want to talk to you about. But not tonight.’

The threat of the conversation-to-come loomed over me as the last vestiges of sleep fell away. There was a knock at the door and a girl in shell-pink uniform came in carrying a tray. She had thick fair hair pulled up into a ponytail and a stern expression. ‘Your breakfast.’ She placed a single cup of hot water with a slice of lemon beside the bed. ‘It’s a beautiful day,’ she commented, as she pulled back the curtains and warm sunlight flooded in. ‘You’ve had your programme explained to you.’ She picked up the printout on the table and checked it. ‘Do you know where to go for your first appointment?’ She pressed a hand on my foot under the bedclothes. It was a professional touch, designed to reassure and give the illusion of expertise. ‘Enjoy your day.’

‘My body is a temple,’ I muttered, and sipped the hot water. On the breakfast-satisfaction index, it had a long way to go.

At home, Felix would be staring glumly into his cereal bowl as he did every morning. Breakfast was not Felix’s thing. ‘Not hungry.’ Lucas would have eaten his already, quickly and efficiently. They had grown cunning and wily, accomplices in deception. When he thought I wasn’t looking, Felix slid his bowl to his brother. I watched for that. Nathan and I had discussed the prospect of Lucas becoming all-powerful over Felix. Nathan had scratched his head and said, without a trace of irony, ‘It’s the law of the jungle. They’ll have to learn.’

‘That’s strange,’ I had said. ‘Usually I’m the toughie, and you’re the softie.’

‘Times change,’ said Nathan.

They had. They had. Times had changed out of all recognition.

I picked up the phone and called Eve. ‘Everything all right?’

She sounded hoarse and tired. ‘I think.’ ‘Yοu think?’

She coughed, a nasty sound. ‘It is all right.’

Nine o’clock. Fitness class. I went through the motions. Squeeze pelvic floor (now they tell you). Control breathing. Contract sitting bones and concentrate on hip flexors. The language and the commands issuing from the lips of a slender instructor in grey sweats were familiar. Their aim was that unreachable perfection. That was how she made her living.

‘Stretch.’ ‘Flex.’ ‘Bend.’ Along the way to this moment, I had picked up another language, now more familiar than this one, which was full of commands like ‘Wash behind your ears’ and ‘Just you get into the bath’ and ‘I’ll have no more nonsense’. Its aim? To get me through the day intact, and to end up with a pair of fed and washed boys.

Ten thirty. I climbed naked into a contraption that resembled an iron boot, and was encased in mud to my neck. It was not an entirely pleasurable sensation. An hour later, I was hosed down by another honey-blonde in a white uniform. She directed a stream of water on to my torso. I yelped. It was ice cold. The girl smiled encouragingly. ‘You’re doing very well, Mrs Lloyd.’ Her gaze slid over my stomach and hips.

I grabbed a towel and wrapped it round me. Used as I was to nakedness at the gym, I had not until this moment appreciated how delightful and desirable modesty was.

After each procedure, the girls in charge – the white uniforms – wrote a report and slid it into the plastic folder that every client carried around.

One o’clock. Wearing dazzling white towelling dressing-gowns, Gisela and I met for lunch: French beans and walnuts in a lemon dressing. The dining room was sunny, with a view of an immaculate English garden in which delphiniums and poppies mingled with exotically shaped foliage.

‘My report card?’ Gisela seemed distracted. ‘Oh, it’s fine. Except they think my diet’s unbalanced, which I assured them it was not.’ She pulled herself together. ‘Have you rung home? All under control?’

‘Eve sounded a bit strange, but so far so good.’

The dressing on the beans had been made extra, extra tart and the inside of my mouth puckered at the first mouthful. I had never cared for lemons. A tall, tanned man at the adjacent table was gazing with unabashed horror at the plate of mung beans and tofu that had been placed in front of him. He looked across to me, and I found myself smiling in sympathy. He shook his head, and smiled back.

Gisela was not enjoying her meal. Unusually, she was jumpy and unsettled. I forced down a mouthful. ‘I guess Marcus has issued an ultimatum.’

She leant back in her chair.

‘He’s called your bluff,’ I went on. ‘It’s either Roger or him?’

Gisela picked up a spoon and attacked the small slice of paw-paw balanced on a piece of melon. ‘It’s very inconvenient of him to make a fuss at the moment.’

‘Poor Marcus.’

The corners of Gisela’s mouth went down. ‘He knew the situation.’

That was irrefutable, and I pondered the rules of Gisela’s life. Was Marcus a permanent lover or was he only permitted to be so between husbands? Was there a code of practice for this sort of thing? The melon on my plate was unripe and frigidly cold, and my teeth jumped as I bit into it. ‘What are you going to do?’

She tensed. ‘That’s what I want to talk about.’

‘I’m touched that you feel you can confide in me… and this is wonderful,’ I gestured to the room, ‘but I don’t know that I can help.’

‘I’m surprised.’ Gisela was taken aback. ‘You’ve been there. In your time you’ve been ruthless, and I wanted your clear head.’

I absorbed this in silence. After a moment, I said, ‘But you knew that, one fine day, you’d arrive at this point.’

She sighed. ‘I tried not to think about it because I knew that if I did I’d lose my nerve. Even I thought how peculiar and far-fetched the set-up was. Marcus accepted that I wasn’t going to marry him until he began to make some money. He had other women too, and whenever I was free he wasn’t, and vice versa. The timing was hopeless. But I always told him he was free to go, and he could have abandoned me years ago. It’s only now that he’s put his foot down. I never quite meant not to marry him. Things didn’t work out quite right.’