‘You're really good at this,’ I tell her. ‘Most people get the steps mixed up, or they rush and then they get in a mess.’

‘Mum says I'm mef-od-ical.’ She pronounces the word carefully. ‘It means I do things in the right order.’

‘That's a big word for someone your age.’

She shrugs. ‘I learn lots of big words in hospital. Like “pulmonary” and “cardiothoracic”.’

Something catches in my chest. She shouldn't have to know those words.

‘You know what I think?’ I say, connecting the pool filter piece. ‘I think you're the toughest person I've ever met.’

She looks up, surprised. ‘Tougher than you?’

‘Way tougher. Look at these muscles.’ I flex my arm, making her giggle again. She’s so tiny. So slight. Way smaller than Elsie, who’s the same age as her and sturdy as fuck. ‘But you? You've dealt with more hard stuff than most adults I know, but look at that smile! That takes real strength of character.’

Her small fingers pause on a LEGO brick. ‘Sometimes I get scared though.’

‘Of course you do. Being brave doesn't mean not being scared. It means doing what you need to even when you're terrified.’

‘Like Mummy,’ she says quietly. ‘She gets scared a lot that the doctors won’t be able to help me. When I waked up after my operation she cried. But she always pretends she’s happy.’

I swallow hard. ‘Your mum is the second toughest person I've ever met.’

‘Is she going to go swimming at your hotel?’

‘I hope so. She definitely deserves a swim, doesn’t she?’

‘I wish I could go swimming,’ she says idly, like it’s a faraway dream.

I frown. ‘Can you swim?’

‘Yeah, but it’s really tiring, so I’m not allowed to do it,’ she says. My heart bleeds afresh for the basic fucking parts of childhood that she’s missed out on.

‘Well, my apartment block has a pool, so you can definitely come swimming any time you like.’ Her smile of astonishment is like crack, and it has me forging on impulsively. Fuck me, she’s so like her mother. They’re peas in a pod. And, just like her mother, her smile makes me want to jump through every hoop there is. ‘And my sister and parents live in the countryside, and they have outdoor pools and lots of ponies, so maybe you can come out and have some fun before the summer holidays are over. You have to put that swanky new valve of yours to good use, after all.’

In the back of my mind there’s a niggling worry that Marlowe would call promises of pools and ponies “buying Tabby’s affection”, but she can go take a running jump.

This isn’t about me playing games or using my money to worm my way into her or her daughter’s hearts.