He’s silent and runs a finger down a scar in the tree’s bark. I want to hug him but he’s not that into hugs.

‘Are there lots of parallel universes, then?’ he asks. ‘One for every single time you make a big decision or something big happens to you?’

‘I think so. But Sylvie says it might be small things that make your life branch off, too …’

‘So each of us must have thousands of parallel universes, all going along at the same time as this one.’

‘Yes. And I guess another version of our circus must exist in at least some of those other universes.’

In the distance, Dad whistles for me; one long note, which is Morse code for T. We ignore it. ‘I kind of heard Mum’s voice earlier …’ Even as I’m talking to Kit, my ears are tuned to every little sound around us, in case her voice comes through again.

He doesn’t look surprised. ‘I hear my dad talking me through difficult trapeze routines sometimes.’

‘Mum’s not dead, though,’ I say hastily. Please, don’t be dead.

‘Why can’t she bring herself back?’ he asks.

‘Something must have gone wrong,’ I say, as if that something might not be completely catastrophic.

‘So you’ll go and get Merry from this parallel universe?’ asks Kit, as if that’s a perfectly normal thing to do.

‘That’s the plan,’ I say brightly, though I don’t know how I’ll persuade Dad. And then there’s the darkest possible dark. My mouth is suddenly dry and my tongue feels strange and thick.

I try to focus on the leaves around us, shifting and glimmering in the breeze. Then I think of the fallen tree up at Flat Rock, and its hundreds – or maybe thousands – of leaves, now slowly drying out and curling in the sun. What if I were to accidentally strike down this tree we’re sitting in? I close my hands into fists just in case a finger points at the tree or Kit, and have a chilling thought: What if I could kill a person by pointing at them? I turn my head so Kit can’t see that thought on my face.

‘How do we listen to this tree, then?’ he asks.

I rest an ear on the tree’s warm bark and he does the same.

‘Close your eyes,’ I tell him. ‘And say, I am listening.’

I watch him whisper the words. His face is so familiar to me that when I was younger I was surprised to see my own face in a mirror. If these trees are all sisters, then Kit and I are brother and sister.