My gaze drifted past the figure on the sofa to the perfectly normal London view outside seven Lakey Street. The trees seemed weighed down with grime, and the pile of rubbish outside Mrs Austen’s flat opposite more than usually noxious. This type of exchange between Nathan and me had become commonplace and held no surprises. What kept me in a state of perpetual astonishment, bewilderment, even, was my miscalculation in having got myself into this position in the first place.

Never complain. ‘What about the Frosts?’

Sue and Jack were Nathan’s very special friends. They were also Rose’s special friends but they were not my special friends. The reverse, in fact, for I was – Sue had been heard to say – a husband-snatcher and a home-breaker.

I couldn’t deny either.

As a result, Nathan was frequently invited to their house a couple of streets away for cosy evenings but I never set foot over their threshold. What they talked about I don’t know, and I never asked. (Sometimes I amused myself by imagining the conversational hole around which these special friends tiptoed.) Was Nathan disloyal? No, he needed to see his old friends – but nobody, nobody, appeared to note the irony in the situation: both Frosts were on their second marriage.

‘Would they come, do you think?’

The hissing noise, which meant ‘I don’t think so’, issued from Nathan, and his eyes flicked to the painting above the mantelpiece. It was of Priac Bay in Cornwall, by a Scottish artist, and rather dull. But Nathan liked it and, frequently, I caught him peering into the turquoise-paint depths of the sea at the base of the cliffs.

‘No,’ he said.

The outlook on the friends front was grim. ‘What about the Lockharts?’ They were also friends of Nathan and Rose.

Nathan sprang to his feet and removed a fleck of something from the bottom right-hand corner of the painting. ‘Minty, it’s no use flogging dead horses. They feel strongly…’ He did not have to finish the sentence.

I glanced down at the list of guests, which, so far, included only work colleagues. ‘Did I mention that I met Sue Frost the other day in the supermarket and I tried to sort things out?’

‘Actually, she told me,’ Nathan confessed, ‘but she didn’t go into detail.’

I found myself inscribing two heavy underlinings on the list. ‘Well, I will. I asked her why, since she and Jack were both on their second marriages, I’m banished from their court. What makes me different from them?’

Sue Frost had tapped her pink suede loafer on the ground and peered over a trolley stacked with vegetables and cleaning aids. Her cheeks had flamed in her pretty but obstinate face as she replied, ‘I would have thought it obvious. I’m not the one who left my first husband. I wasn’t the party who broke up a marriage.’

‘So…’ Nathan shoved his hands into his trouser pockets. He put on the face he used for tricky business meetings: unreadable. ‘What did you say?’

‘I said I wanted to get the situation as she saw it absolutely straight. As a second wife, Sue was OK because her first husband had had the mid-life crisis and left, while I, as the second wife and the object of the mid-life crisis, was not. I wanted to know what the position would have been if she had driven her first husband away.’

That amused him. He stopped looking haunted and relaxed back into the kind, clever man he was – the man who beat his chest and produced gorilla noises to make the twins laugh, and the man who had recently persuaded the Vistemax board to rethink their position on the future of newspapers. As an able man he could do both.

‘And?’

‘She vanished into the frozen-fish section.’

Nathan uttered a short, barking laugh. ‘You won that round, Minty.’

‘What I really wanted to ask her was why I’m a home-breaker and you aren’t.’

Nathan met my eyes steadily. In his lay the detritus of painful history. ‘I’m blamed too, Minty.’

‘No, you’re not. That’s the point.’

His gaze drifted towards the painting, as if he were seeking reassurance in the shimmer of water, rock and cliff.

‘In Sue’s eyes you’re still married to Rose. There’s nothing I can do about that. In the complicated hierarchies of marital morality, Sue gets a tick, Rose gets sainthood, and I get the cross.’

Any trace of amusement had been wiped off Nathan’s features. ‘Would you prefer it if I didn’t see the Frosts any more?’

In Successful Relationships, a manual that, in the past, I had studied diligently, it says that to bind a partner you must release them. I’m a great believer in self-help manuals – although, lately, I have found myself wondering if they only add to the confusion by suggesting problems you didn’t know you had. However, mindful of Successful Relationships’s teachings, I said, ‘Nathan, I insist you see Sue and Jack Frost.’

I offered him the unfinished guest list – Nathan’s boss and his wife, Roger and Gisela Gard, and my boss and his wife, Barry and Lucy Helm. ‘We haven’t got very far.’

Before I married Nathan, I’d pictured my life so differently. Who didn’t dream of a fine, harmonious household in which friends and family gathered? ‘It’s no use asking Poppy and Richard, I suppose? And Sam and Jilly are too far away.’

As always, Nathan brightened at the mention of his elder children. ‘Poppy is very busy,’ he said carefully, ‘and I don’t think Sam’s due up in town for some time. And he’d probably go and see… his mother.’

If I had to choose one overarching objective in my marriage it would be ‘get rid of Rose’. Scrape her away from the surfaces of this house, then dig deep, as she had once dug the garden, to exhume the Rose roots that throttled Nathan and me. She was everywhere, I was in no doubt of that, and her power lay in my victory and her suffering.

‘Minty.’ Nathan disliked it when I ignored him, which was one of my weapons. ‘I’m still here.’

I turned my head. ‘Don’t mention Rose, then. Don’t. Don’t.’

He came over and hauled me to my feet. ‘I wasn’t thinking.’ He placed his hands on my shoulders and looked into my eyes.

‘We have to try,’ I murmured. Automatically.

‘Course we do.’

He smelt of vetiver and – faintly – of tarragon and garlic. Whatever went on in Nathan’s head was only half my business, but there were times when I couldn’t face even a tiny percentage of the mixture of disappointment and fatigue that I suspected churned within him. I craned my head back and took a good look at him. It struck me that he was very pale. Nothing a useful dinner party wouldn’t put right. I reached for another of my weapons and slid my arms round his neck. ‘Come here.’

After a while Nathan saw the point, which I had known he would. ‘Sometimes, Minty,’ he played with my fingers, ‘you can be so sweet. And sometimes…’

‘And sometimes?’

‘Not.’

He wanted to say more, but he would never get it out in a month of Sundays, and there was no point in wasting more time. I placed a finger on his lips. ‘Hush.’

I returned to the guest list and to my private thoughts, which were many and various – not least why it was that in such an apparently godless world, when anything went and everything possible was done, I was the object of such censure.

Later, getting ready for bed, I discovered a yellow Post-it note stuck to the back of my hairbrush. On it, Nathan had written ‘sorry’.

At seven fifteen a.m. on the day of the dinner party, I picked up the phone to Five-star Caterers: ‘Just checking that everything’s OK for this evening.’

A voice reeled off, ‘Ten twice-baked cheese soufflés, chicken with ginger in soy and sherry sauce. Bitter cherries in maraschino served with a frangipane and pâte sable tart.’

I had toyed with having menus printed because I relished the names of the dishes, but Paige had put her foot down. ‘Nope. Not the thing.’

‘Not the thing’ was annoying, but I bit my lip. Paige was a neighbour and also a good friend. She had never met Rose so her relationship with me held the extra sweetness of the untainted. Paige knew what was what, and during her years as an international investment banker, she had been on the receiving end of many dinners like this one. I needed guidance through the pitfalls. Paige provided it. Enough said.

Paige had also given the thumbs-down to sticking taffeta bows on the chair backs, which, I reckoned, would be the finishing touch. ‘Finish the guests off, more like.’ She hooted with amusement. ‘For goodness’ sake, you’re not a brothel.’

Yes. Someone had to tell me what was what. I knew that much.

I’m a fast learner but, as the taffeta-bows incident indicated, there were gaps in what I knew, and what I understood – puzzling, slippery points of taste and appropriateness.

Knives, forks, wine glasses… I checked the place settings on the dining-table, which I had laid at six thirty that morning – i.e., before the twins were up. Only the flowers were missing and I had ordered an exact match of an arrangement I had seen in Vogue. Hovering in the doorway, I gave the mise-en-scène a final sweep, and concluded that there was nothing to embarrass Nathan, and everything to enhance his reputation.

I nipped back to the table and adjusted the angle of a knife.

My watch said 7.20 a.m. Say goodbye to twins, race to hairdresser, then on to work.

Eve – twenty-two, Romanian, not a threat – was bathing the boys when I arrived home at six fifteen.

As I let myself in, the draught made the cat-flap in the back door – long since disused – open and shut with a bang. For the hundredth time, I cursed it.

‘It’s Mum!’ Lucas’s high-pitched voice. I stopped and waited.

Sure enough, Felix echoed, ‘It’s Mum.’ I hadn’t clocked in until I heard the echo, which meant everything was fine.