But there we are. Moving in real time. But, instead of the carpet, on the screen I’m paddling through water. Among silver fish that flick their tails and sharks that circle above us. And I put out my hand to one and my fingers pass right through it.

‘Green screen,’ Dad says, watching me. ‘You can be anywhere you want in this room, kiddo.’

I look around. At Cecelia fist-bumping herself for finally getting into her wetsuit. And at Mum, who has disappeared from the screen completely now she’s covered in green. And I can’t think of a better place in all the world to be.

First – we swim. Mum holds me up as I pretend to paddle and, on the screen, it really does look like I’m floating. Cecelia pushes herself across the carpet in a backstroke and attempts to punch a shark until I shout at her.

And then – we’re floating through space. Cecelia makes throaty Darth Vader noises and Dad calls out from behind the camera all the things that are inaccurate about her impression. Mum helps me roll, spin, float above the world, where the stars twinkle and an asteroid bursts across a black sky.

Then – we’re at a party. In front of a heaving mass of bodies, moving in time to music we can’t hear. Cecelia dresses us in plastic crowns and feather boas and complains loudly about there being no music until Mum rolls her eyes and starts singing one of her old songs.

Cecelia grabs my wrists and makes my arms dance for me – even though I know all the moves enough to know she’s doing them wrong. And I laugh – laugh so hard that I can’t see anything but a blur of green and plastic ribbons and Mum’s wide smile.

‘This is amazing,’ I say as Cecelia lets me go.

Dad grins. ‘Oh, you ain’t seen nothing yet.’

He fiddles around in a box for a moment and then brings something out that looks like a blackened scuba mask.

‘Right. Cecelia – you break this and I’m going to make you pay for it in Pop-Tarts for the rest of your life, okay?’

He straps it on my head and the world disappears in darkness.

‘What do you mean, me? I’m not even the one wearing it – Alice is!’

‘Yes, but Alice is sensible,’ Mum says, clicking what feels like headphones over my ears.

‘I’m not always sensible,’ I say, thinking of Rowan and me breaking into tunnels and skipping school.

Cecelia scoffs and I kick her.

‘Okay?’ Dad says in my ear.

‘I think so … But I’m not sure –’

‘Patience!’ Cecelia shouts.