That’s disappointing. ‘Really? She was sharp, which is different. We said what we meant, in those days.’

Erica laughs – Leonie’s laugh, from the days before she only laughed in sarcasm or in spite – and the pain of loss crackles bright in Vee again. ‘And you don’t say what you mean now?’

And now there is a sudden jab in Vee’s head, a reminder maybe. ‘Not always.’ She adds, ‘Thank you for taking care of me, before the march. I appreciate it.’

There’s the slightest flicker of shock in the muscles in Erica’s face. Her eyebrows rise and fall, her head moves backwards, just a fraction, and Vee thinks: when did I become the person who shocks people when she thanks them? This change could be due to the tumour, of course, but her heart – and she has always trusted her heart, and has no reason not to now – says, quietly, that she became rude long before she became ill. ‘Manners and a smile cost nothing’, her dad used to say. He’d be unimpressed by what she has become, retrospective exhibition at the Photographers’ Gallery or not. She closes her eyes, sees him loading her possessions into a borrowed van to help her move to London, even though he would rather she stay in Colchester with him. She needs to do better by Erica. That will be something.

‘I was glad I could help,’ Erica says.

‘I’m sorry I couldn’t do more, at the march.’ She’d watched as Erica was taken away, but experience told her that there was nothing to be done but wait for news. She’d emailed Erica that evening, saying she hoped that she was OK, and then she’d gone to bed, unable to do anything else with her worn-out body and the steadily expanding pain in her head. The distance from action to consequence is ever shortening. The march was too much for her, and she paid for it, the next day lost in painkillers and half-sleep, cold rum and hot toast. But she didn’t care. It was worth it, to be back on the battleground. And to take someone to their first march.

‘It sounds selfish, but I quite enjoyed being arrested. Well, detained. Marcus wasn’t impressed.’

Vee is seeing her mind as a roll of film, full of a lifetime’s worth of photographs, now overexposed to light, the images it held eaten away. And yet, however much of her brain the disease has destroyed, there are things that she is still sure of. And one of them is that Erica is not happy. There’s something brittle about the way she talks about her family, and her emails arrive late at night, when any sane person would be asleep, or with their loved ones, if their loved ones are nearby. Help a sister out, Leonie says, as clearly as if she was here. Vee will try to be kind.