As I attach the adapter, Grandad lights one of his roll-ups then picks up a crossword puzzle. ‘Looking forward to Saturday?’ he asks, catching my eye.

‘Bit nervous,’ I say, ‘but I’m trying not to think about it.’ On Saturday, I’m helping Grandad do a workshop at the science centre. He’s done them before and usually I just watch from the audience, but this time I’ve volunteered to be his assistant. Although I haven’t told Grandad this, I’m hoping that passing him balloons in front of an audience will take me a step closer to using my voice in front of an audience. That’s the plan, anyway.

‘You don’t need to be nervous,’ he says. ‘You’ll just be standing at the back and keeping me organised.’ He nudges me and grins. ‘You and me, Meg, blowing kids’ minds about the cosmos … and blowing stuff up. I can’t wait!’ He lets the ash from his cigarette drop on the floor.

I stare at the glowing tip of his cigarette and try to imagine me standing in front of all those kids … Hang on, I’m staring at the glowing tip of a cigarette!

‘Grandad, tell me you’ve turned the gas off …?’

‘It’s fine,’ he says, waving the smoke over his shoulder.

I snatch the cigarette out of his hand and stub it out. ‘It’s not fine.’ Just then, I hear a shriek from outside. ‘Is that Elsa?’

‘She’s exploring the garden.’

‘Grandad!’

‘What? I couldn’t keep her in here with me when I was smoking and doing this dangerous job. Anyway, Pongo’s looking after her.’

‘Pongo’s a dog and Elsa’s … what, one and a half years old?’

‘No. Wasn’t it her birthday a couple of months ago?’ For a moment, we try to work out exactly how old Elsa is, but we give up when she starts to cry.

I find her sitting in some daffodils, her hands and hair full of soil. Pecking the ground next to her is one of Grandad’s bantams (also covered in soil). When Elsa sees me, she stops crying and starts to laugh and pump her arms up and down, saying, ‘Buc, buc.’

Is she being a chicken? Who knows … I pick her up, holding her away from me, and carry her back to Grandad. ‘Where’s Elsa’s pushchair?’ I say.

‘Your mum dropped her off in the car.’

Great. Elsa weighs a ton. This is going to be one long walk home. Then I spot Grandad’s ‘funky’ Union Jack shopping trolley. Would I be breaking some sort of baby rule if I put Elsa in there? Actually, I don’t care if I break a baby rule, I can’t let anyone from school see me with a baby in a shopping trolley.

‘Looks like I’ll have to carry her home.’ I pass her to Grandad while I get Pongo’s lead.

Elsa stands on Grandad’s lap and tries to grab at his crossword puzzle. ‘What’s “Colourless gas; atomic number eighty-six”?’ he asks.

‘Radon.’ I take Elsa and her muddy fists cling on to me. I shrink away, but she just holds on even tighter. ‘You knew that,’ I say. ‘Stop giving me the easy ones.’