Of course she knows: she’s lived through this before, and now, thanks to me, or strictly speaking thanks to my father and his rogue DNA, she has to live through it again. And it’s not as if I’ll do anything sensible like dying nice and neatly with all my faculties intact, holding her hand and thanking her, with a serene look on my face as I impart words of wisdom to live by to my children. No, my annoyingly quite young, reasonably fit body will linger on long after I’ve checked out of my mushy little brain, right up until the moment when I forget how to breathe in and out and in again. I know that’s what she is thinking. I know the last thing in the world she wants is to watch her daughter fade away and shrivel up, just like her husband did. I know it’s breaking her heart and that she’s doing her best to be brave, and stand by me, and yet … It makes me so angry. Her goodness makes me angry. All my life I’ve been trying to prove that I can grow up enough to not need her to rescue me all the time. All my life I’ve been wrong.

‘Actually, Mum, I am the one who can stick my head in the sand,’ I say, staring out of the window. ‘I am the one who can completely ignore what is happening to me, because most of the time I won’t even notice.’

It’s funny: I say the words out loud, and feel the fear, there in the pit of my stomach, but it’s like it isn’t part of me. It really is like it’s happening to someone else, this terror.

‘You don’t mean that, Claire,’ Mum says crossly, as if she really thinks that I mean I don’t care, and not that I’m just saying it to annoy her. ‘What about your daughters?’