I pushed aside the notes. The idea required further work because it was still gestating. It needed time to grow wings.

I rubbed my eyes and ran my fingers through my hair, which required cutting – goodness knew when that would be possible.

What had Nathan been right about?

What had he and Rose agreed about me?

I was on the switchback again.

I went to make some tea and, on the way, glanced up at the landing where the ironing-board was and where Rose, when she lived here, had placed her desk. She was still in this house, Nathan too.

I put the kettle on, unlocked the back door and went outside into the summer night.

What had Nathan and Rose decided between them?

I sat down on the bench and ran my fingernail along the table. There was lichen growing on it, and it needed scrubbing. I remembered Nathan sitting opposite me at this table. We had been married for three years and one day. Because it was such a warm evening, we were having supper outside, seafood pasta – I was eating the seafood without the pasta – and we had embarked on a negotiation as to where we should take a holiday.

‘I want somewhere hot,’ I said, as I always did so my pitch held no surprises.

He dug his fork into the pasta, twirled it expertly, then lifted it to his mouth. ‘And I want to go Cornwall,’ he said, as he always did.

‘I’ve looked up a place on Rhodes. Nice villa by the sea. The boys would like it.’

‘The boys are too young. When we took Sam and Poppy…’ Nathan did not continue. He put down his fork and looked everywhere but at me.

That was the moment when a voice in me articulated clearly, ‘Do you realize you’ve taken on enough history to fill a library?’

I got up, went inside and rattled in the cupboard for salt. I was ashamed and devastated by the revelation and also, curiously, calm because everything was now crystal-clear.

Nathan would never let go of his past life, could never let go.

He followed me into the kitchen. ‘Minty, this has got to stop. I can’t pretend I didn’t have Poppy and Sam.’

‘No,’ I said.

Upstairs, one of the twins called. Nathan and I turned our heads in the direction of his cry. ‘You or me?’ asked Nathan.

On that at least we were united.

Now, in the kitchen, I ran hot water into the sink and plunged my chilled hands into it. Then I boiled the kettle and took a cup of camomile tea up to bed where I drank it. I switched off the light and lay down. After a while, I put out my arm and let it rest in the space that Nathan should have occupied.

Rose did not reply to the messages I left on her answer-phone. I allowed two days to elapse. Then I took myself round to her flat after work.

She answered the door. She was dressed in a skirt I recognized from Prada, a leopard-print cardigan, and a necklace of large wooden beads. She looked wonderful, and not very surprised. ‘I suspected you’d turn up sooner or later.’

She did not invite me in, so I summoned my best brand of gall. ‘You didn’t answer my calls. I’ve come to sort things out.’

Rose kept her hand on the door, and I said, ‘Rose, if we get this over and done with, then it’ll be over and done with.’

Eventually she stepped aside. ‘Come in.’

The sitting room was a mass of flowers and smelt gorgeous. ‘I’ve just landed a one-off slot on a gardening series for television,’ she explained. ‘I’m doing small city gardens. People have been kind and sent flowers.’

‘Who with?’

‘The Activities Channel, but it’s being made by Papillon. It probably won’t get a large audience, but you have to grab these opportunities. Anyway, it’ll be fun.’

‘Papillon? That must be Deb.’ I glanced at the label on a huge bunch of lilies, which read, ‘Love from Hal’. ‘How is Hal?’ I asked.

‘Fine. Busy’.

‘I often wondered if you’d marry him.’

‘As it happens, he has asked me.’ Rose pointed to the blue chair. ‘Sit down, Minty.’

I avoided the blue chair where Nathan had died and sat on the sofa. ‘Why not marry him?’

‘I like what I am. I’m fine as I am. I don’t want change anything,’ Rose replied, but her voice was not entirely steady. ‘Hal’s the sort of person who never leaves you, and he hasn’t. So…’ She fell silent. ‘I don’t know what to think. I may or may not. Probably not. I don’t want the disruption. I’ve got used to thinking of myself as independent.’ A flash of uncertainty and doubt. ‘It’s difficult at my age… so…’ She switched the subject. ‘Say whatever you want to say, then go. Let’s not waste each other’s time.’

My mouth and throat were dry, but I couldn’t bring myself to ask her for a drink. ‘I want to know about you and Nathan.’

‘Nathan and I were married. We had two children. I had a good job. Then I hired you and brought you home to meet him over spaghetti. You know the rest.’

‘No,’ I said. ‘That’s not what I am asking.’

Rose was keeping something back. The light played on her honey hair and creamy skin. In the past, Nathan had touched that hair and skin. They had belonged to him.

Thirsty, and burning with humiliation, I asked the question that had to be asked: ‘Rose, did you take Nathan back as a lover?’

Rose shifted in the chair. Slender but not too slender, toned and groomed, she was a world away from the frazzled working mother I had first encountered in the Vistemax office. Yet she was vulnerable too. It’s difficult at my age. And vulnerability had its own eroticism. Of course Nathan would have wanted her back.

She placed her hand on her chest in the region of the heart. ‘It feels like a stone sitting on my chest, mourning Nathan. Like a gigantic attack of indigestion.’

‘I know,’ I said.

We could ask each other, Do you weep for him, like I do?

‘Do you?’

You’re not answering the question.’

‘That’s because I’m not going to.’

I bit my lip. ‘Tell me, Rose. What was it you and Nathan decided?’

‘He said you were ambitious.’

‘So was he at my age. So were you. You had a fight with him about going back to work.’

The hand on her chest curled into a ball. ‘It’s irrelevant now. Old, old ground and I don’t wish to go over it.’

‘Old ground for you, perhaps.’ I closed my eyes for a second. ‘But Nathan didn’t like it, and it was a source of friction.’

‘For God’s sake, Minty, what do you want?’

‘I suppose…’ I said miserably ‘… I want to tell you that he wasn’t really happy with me. And that he regretted leaving you.’ I hesitated, and then I forced out the words through gritted teeth. ‘Did he come back into your bed?’ Rose made a noise between a laugh and gasp, but I ploughed on: ‘Nathan had been there so many times before…’ Yes, he had shared the everyday language of small noises and touch with Rose. He had listened to her breathing in the night, heard her clean her teeth, fill the kettle… ‘It wouldn’t have been such a big step.’ Rose held up a hand to stop me, but I ignored it. ‘I could never share the long history you had with him. I could never compete. You were always there, ahead of me. Always.’

‘Stop it, Minty.’

I had wit enough left to obey her.

Rose flashed a wry smile. ‘I want never gets.’ It was a saying we’d used often in the office. Once. Years ago. Timon, the editor, had always wanted more books, fewer books, different ones. I want never gets. Except, in that case, ‘I want’ usually did get. She continued, ‘When Nathan first told me he was having an affair with you, I asked him why he’d told me. If someone’s having an affair, they should be very clever and very secret. I still believe that.’

‘Nevertheless I need to know.’

Rose’s smile had vanished. She leant towards me to emphasize her point, and I smelt her jasmine scent. ‘I don’t have to tell you anything, Minty.’ She spoke without malice, almost gently. ‘You lost the right to my confidences long ago. I don’t have to discuss anything with you and I certainly don’t feel I have to help you sort things out.’

She got up and disappeared through the door, then returned with a bottle and glasses on a tray. ‘You’d better have some of this. Hal brought it from Italy.’

As I accepted a glass, my blouse dug into the flesh under my arm. ‘The boys ask after you quite a lot.’

Quick as lightning, I picked up the flash of delight that lit her face. ‘The boys…’ Her voice was soft, almost possessive. ‘They are sweet.’

My instinct was to hiss, ‘Keep off my sons.’ Unreasonable, I knew. I looked down at my hands and struggled for mastery of myself. ‘Old friendships and old loyalties. Do you remember? You talked about them at that supper when I first met Nathan. How hard it is to shake them off.’

She smiled grimly. ‘Believe me, I could shake you off, Minty, with no trouble at all. It wouldn’t take much.’

She meant it, and I flushed – not with anger but despair. As the woman who had pinched her husband, I was culpable, pitiable and all the other things that Rose cared to name. And yet all those years ago, I had witnessed her rush into the office, too-pink lipstick smudged, sweater ill-fitting, swearing that Nathan/the children had been difficult/demanding/cross, and I’d thought it was the other way round.

I drank my wine, and looked around the room. In its calm, ordered magnolia and cream, with the blue touches here and there, it reflected what Rose had become. And it was a room that had been arranged entirely to the satisfaction of its occupant. ‘There are advantages to living alone,’ I remarked.

She understood what I meant. ‘Actually, yes.’

We exchanged a glance. Funnily enough, we do understand each other Rose put down her glass and said, ‘Nathan and I were married for a long time. We knew each other well. Just as… just as… you and I do. It was easy to pick up conversations.’ She got up and walked over to the window ‘My life with Nathan was private until you came along. If our marriage had bad patches, and areas of blindness, it was ours and it worked, until you prised it apart. Then everyone took a good look, and it was open house.’ She turned and stared at me, calm and steady. ‘You’ll admit that I don’t owe you anything, Minty. No explanations. No loyalty.’