I shake my head. ‘No, not a planet like Earth, a planet better than Earth.’ Just talking about this is making me feel more awake. ‘Our sun has a lifespan of up to ten billion years, right?’

He nods.

‘Smaller suns live for longer and might support a planet richer than Earth.’

Ed’s got a half-smile on his face, and I know why: I never normally talk like this, but suddenly I can’t stop the words from tumbling out of me. ‘When you think about it, Earth isn’t that great. Around ninety-eight per cent of its surface is uninhabitable. We can only live on two per cent of it.’

‘So you’re not that impressed by Earth?’

I shake my head. ‘It’s too crowded.’

We fall quiet, then Ed says, ‘Now’s when you’re supposed to ask me what I’m doing for my speech, Meg.’

‘Oh, right. So … what does space mean to you?’

‘Space will be the saviour of Earth!’ he says, spreading his hands wide, then he sits back looking pleased with himself. ‘I’m going to talk about how satellites and space research will help us sort out all our environmental problems.’

‘Right,’ I say.

‘Adults love it when young people talk about the environment. It makes them feel like they’re leaving the planet in safe hands.’

‘You’ve thought this through,’ I say. Honestly, I hadn’t even considered what adults might want to hear. Once again, I have that worrying feeling that Ed King is just one step ahead of me.

Ed shrugs. ‘I’ve thought it through because I want to win.’

‘Time to pack up!’ calls Ms Edgecombe, and I turn away from Ed and start stuffing my books in my bag.

As we’re filing out of the room, Ms Edgecombe reminds us to bring in our permission slips for the Sussex University trip next week. As I’m jostled and shoved in the corridor, I try to run through what I’ll do with Elsa. We’ll be getting back too late for me to pick her up from nursery. Suddenly, every single aspect of my life has become more complicated – even this trip that I’ve been looking forward to for so long.

Outside school, I see Bella go off with her friends and Ed climb into the back of a black Range Rover. I get a glimpse of a cream leather interior before the door slams shut with a heavy clunk. Then the engine purrs into life and the car pulls smoothly into the traffic.

I check my phone: I’ve got ten minutes to get to Little Acorns. I grab hold of the straps on my rucksack and start to run.

FIFTEEN

‘I need eight pounds, Grandad.’ I’m curled up on his sofa watching In the Night Garden with Elsa. ‘Little Acorns charged me a fine for being late.’

In the kitchen, a pan bangs down on the stove and I hear pasta splash into water. ‘But you’re never late!’ Grandad shouts back.

‘Well, I am now. All the time. I was six whole minutes late.’