And that’s when Grandad’s landline starts to ring.

‘Be quiet!’ I say to Elsa and I snatch up the phone, covering my free ear to block out her cries.

‘Meg?’ The voice is crackly, distant.

‘Grandad? Is that you?’

‘Meg, thank goodness I caught you! But shouldn’t you be at school by now?’

‘Yes! The competition starts in twenty minutes! Where are you?’

‘Ah, I’m in a spot of bother. I was out on my bike –’

‘Grandad!’ I shout this so loud that Elsa stops screaming and stares up at me. ‘Why did you have to go on a bike ride today?’

‘Well, it wasn’t a bike ride exactly. I was so excited last night that I couldn’t sleep and then I remembered that I still had your rocket up in the attic. I thought it would be brilliant if you walked into the house and saw it sitting there, in all its magnificence! I’ve even made you some rocket fuel and I was going to hide the bottle inside the cone –’

‘I found the cone and the bottle,’ I say, interrupting him, ‘but what’s that got to do with going on a bike ride?’

‘Ah, that’s what I was getting to. I discovered that the bottom of the rocket – the box you sat in – had been eaten – possibly by hamsters, possibly by rats – so I decided to go and get another one from the supermarket. They gave me a real beauty, Meg. It’s even bigger than the original one. Anyway, I was cycling back through the woods, holding the box under one arm, when it happened.’

‘What happened?’

‘I hit a root. When I came round, my ankle was the size of a football. I’m having a bit of trouble walking.’

‘When you came round? Grandad, where are you?’

‘I’m at the bottom of the quarry – you should have seen me fly down it, Meg!’

‘So you’re not too far away –’

‘Don’t worry about me. You get down to your school and win the competition.’ The line crackles and for a moment I can’t hear what he’s saying. The reception is terrible on the Downs. ‘Come and get me later … Maybe bring a friend or two. I’m going to need a couple of people to lean on.’

I press the phone against my ear. ‘If you’ve had a head injury, I can’t leave you up there.’

‘It was a tiny head injury! I’ve got a Lion Bar and a Fruit Shoot, so you can stop worrying about me. You are going to blow their minds about space, Meg, and you are going to go to Houston. That’s your new mission! Poyekhali, Meg! Poyek–’

Then he’s cut off.

I take a deep breath, fighting the panic that’s rising inside me. This is unexpected, but I can work the problem, as long as I stay calm. Should I do what he says and go to school, do my presentation and then go and find him? No. I can’t do that. What if he slips unconscious again, or if he was lying about how badly he was hurt? But how can I possibly go and get him without anyone to help me, and what should I do with Elsa?