‘Yes. Wrong’un. A very brilliant wrong’un.’

I didn’t know how much of what Dad was telling me was fact according to history or fact according to him, but I was so enjoying returning to the parental dynamic in which he was the person with more information and insight than me.

‘Do the transgressions of the artist undermine the pleasure to be found in the art? If you could answer that, you might solve the internet, Dad.’

We both stared at the lilac-grey curves of her body and the brown swirly arms of the chair that held it.

‘Maybe I’ll meet a nice lady here and move her into the house,’ he said. ‘What would your mother say to that?’ I laughed. ‘I’m going for a wander.’ He placed his hands behind his back and walked slowly along the gallery, gazing up at the paintings as he went.

‘All right,’ I said, watching him intently, like a child I didn’t want to lose. ‘See you in a bit.’

I stayed in front of Marie-Thérèse in her red armchair and examined every part of her exquisitely scrambled form. The impossible positioning of her breasts stacked on top of each other, the surreal placement of her mismatched shoulders. How her face was split into two parts, one half of which could be another face kissing the other in profile, if you looked for long enough. Was the second face that Picasso saw symbolic of Marie-Thérèse’s hidden multitudes? Or was it his profile – did he imagine he dwelled within her, his lips on her cheek wherever she went? What would it be like, I wondered, to be seen through such adoring eyes, that they could not only capture you in a painting, but rearrange you to further exhibit who you were? I stroked the rounded right angle of where my neck met my shoulder like it was the hand of a lover and thought about being put inside a Rubik’s Cube of someone’s gaze. I couldn’t imagine ever being studied and known like that.

As soon as Dad and I left the gallery and stepped out into the rush of central London, I could see his brightness and confidence diminish and be replaced with confusion and fear. It was hard to know if it was a symptom of his illness, or whether that was simply a result of old age. Dad – a man who had never lived anywhere but London; who had known its streets off by heart from cycling through them as a boy and striding across them as a man – now looked nervous.

We went to a Hungarian bakery that was a short walk from the gallery. He’d taken me there a few times in my childhood – he loved the wood-panelled walls, the coffee cakes, the surly waitresses he could charm and the fact that it was an institution nearly as old as he was. We sat at a table by the window, and I could see he was hypnotized by passing strangers as he gazed out of the window quietly.

‘What do you fancy?’ I asked. He glanced down at the menu and didn’t respond. ‘One of the coffee cakes?’ I knew not to give him too many options to avoid risk of further confusion.

‘I don’t know,’ he said.

‘I’m going to get a coffee cake. Why don’t I get us two? And some Earl Grey.’ His eyes looked past me and over my shoulder, widening slightly in awe.

‘Goodness gracious.’

‘What?’

‘Don’t look now, but three of the Mitford sisters have just arrived.’ I felt a thud of disappointment and hated myself for it. I knew what I had to do in these situations – Gwen and I had spoken about it a number of times. But I didn’t want to play along with an imagining today. I didn’t want to spend this precious time with my dad in a sad reversed parent–child dynamic in which I knew what was real and he didn’t. I wanted the vital, exacting Dad who could tell me about Picasso’s French chateau and exactly what cakes we should order from his favourite bakery. The charming, silly Dad who’d order chips and put one on his shoulder – a daft gag for weary waiting staff. The Dad who’d draw maps on paper tablecloths. The Dad who’d catch the waiter’s attention at the end of the meal and use his finger to mime writing. I couldn’t remember the last time I’d seen him do that.

‘Really?’

‘Yes!’ he said, with gleeful mischief. ‘Right, have a look now.’ I dutifully turned around to see three women who looked nothing alike, other than they all had grey hair, standing at the counter and examining the cakes through the glass.

‘Ah yes,’ I said meekly.

‘Nancy, Diana and Unity. There they are.’

‘There they are,’ I repeated. ‘Right. Tea?’

‘Nancy must be over from France. I would so love to talk to her. Wonder what she’d make of a Non-U like me.’

‘Mr Dean?’ We both turned around. A man stood by our table – forty-something, soft-faced with masses of thick brown hair and round tortoiseshell glasses. ‘It’s Arthur Lunn. I was one of your pupils, years ago. At St Michael’s.’ Dad stared at him blankly. ‘There’s no reason why you’d remember me. You gave me extra help when I was applying to Oxford. I’m pretty sure it’s the only reason I got in.’

‘So lovely to meet you,’ I said. ‘I’m his daughter, Nina.’ Dad was visibly distracted by the three women at the counter. ‘What Oxford college did you go to?’

‘Magdalen. I was miserable for most of it, but still, it’s probably the happiest my mum has ever been, the day I got my acceptance letter, so I have a lot to thank you for, Mr Dean.’

‘Call him Bill,’ I said. Dad snapped his head back round to us briefly.

‘Yes, Bill’s fine,’ he said.

‘Bill. Feels weirdly overfamiliar to call your teacher by their first name, even as a forty-four-year-old man.’

‘Yes, it’s strange that,’ I said, grasping at platitudes.

‘I was going to try and get hold of you, actually, to let you know there’s a Facebook group in your honour, where lots of your old students talk about you and share stories and memories of you as a teacher. Some really nice old photos as well from results days. I’ll have to tell them that I saw you.’

Dad continued to study the three women.

‘Dad,’ I said gently, trying to get his attention. He focused on us.

‘Did you ever read Love in a Cold Climate?’ he asked.

Arthur politely tried to hide his bafflement. ‘No, I don’t think I did.’

‘You must.’

‘What are you doing now?’ I said, my small talk trying to paint over the cracks of Dad’s conversational logic.

‘I’m a lawyer,’ he said. ‘Which is probably a waste of an English degree. But I think maybe every job is a waste of an English degree.’

‘Yes,’ I said. ‘I think you’re right.’ I was desperate to explain to him that Dad was ill – I was desperate for his long-held memories of Mr Dean inspiring and encouraging him not to be replaced by this disconnected man who could barely say hello.

‘Well, I’d better go, I’m here with my family.’ He pointed over to a woman at a table, getting ready to leave with two preadolescent boys in navy puffa jackets who had their dad’s abundance of brown hair. ‘It was so lovely to see you again. I think about you every time I start a new book. You always told us that literature belongs to everyone and that we should never feel intimidated by it. I say that to my two boys now they’re just starting to love reading.’

Dad smiled at him and said nothing.

‘Thank you so much for coming over,’ I said.

As I watched Arthur and his family leave, I realized he must have been in the photo that I found in the box of Dad’s documents at home – the one of the smiling boy with his parents on graduation day at Magdalen College. I wanted to run after him and explain what was going on. But Dad was too disorientated to leave in the café on his own, and I was worried he would try to speak to the three tribute act Mitford sisters he was so entranced by. So instead I watched Arthur and his family walk out of the bakery and along the road until they disappeared. And Dad and I talked about nothing but the Mitford sisters sighting all the way home.

Mum answered the door in yet another workout ensemble of purple flowery leggings and a grey vest top with a matching zip-up hoodie. On the back of it was an outline of a Buddha in metal studs.

‘Hello, lovey,’ she said to Dad, kissing him on the cheek. ‘How was the exhibition?’

‘Wonderful,’ he said.

Mum placed a precise, glossy-lipped kiss on my face.

‘We both saw The Dream for the first time, which I think might be my favourite of his paintings,’ I said. ‘The colours were incredible in the flesh.’

‘Yes, and we only bloody spotted three of the Mitford sisters! Diana, Nancy and Unity,’ Dad said, while sitting on the stairs to take off his shoes. ‘Wanted to eavesdrop to see if they were talking politics.’

‘Aren’t they all –’ Mum started. I glanced at her, reminding her of our agreement. ‘Right. That’s exciting.’

‘And we went to that Hungarian bakery Dad loves,’ I said, trying to subtly switch topical gears. ‘Ate some coffee cake.’

‘Sounds like you had the time of Riley,’ Mum said.

‘Life,’ Dad replied, holding on to the bannister as he stood up.

‘Sorry?’