Harby shakes his head, turns his face skyward. I look where he’s looking; there are more stars here than I have ever imagined, sprinkled across the sky like silvery freckles. A shooting star fizzles and vanishes … POW! Just like that!

‘I wish … I wish I could go home,’ I whisper, half under my breath.

‘… home …’ echoes Harby.

I smile sadly to myself.

Then Harby nudges me sharply in the ribs.

‘Oi!’ I yelp. ‘That hurt!’

‘Home!’ says Harby again.

I turn to him; there’s urgency in his voice.

‘Home!’ He shakes my arm in excitement. ‘I member home!’

I MEMBER

‘Brilliant!’ I say, breathless too. ‘Maybe that’s where she is, Mothga. At your home! That’d make sense, total sense. Well done, Harby!’ I leap to my feet. ‘That’s where we can go! Where is it?’ I sweep my arm over the vast moonlit forest. ‘Where’s home?’

He screws up his face, like he’s trying so hard to think, to remember. His big hands open and close, reaching for something that’s almost within his grasp. Then he shakes his head crossly. ‘No … I member home … I not member where home …’ He bangs his spear on the ground in frustration.

‘OK,’ I say slowly. ‘Well … maybe I can help … can you describe it to me … I might … you might …’ Hope seeps away again.

Harby stares at me blankly with those ever-dark eyes. ‘Home?’ he mumbles. Then he suddenly stands taller, like an idea has just struck him. He starts to draw on the rock with his spear, a pale grey line.

I peer over his shoulder as he draws one large dome, with a medium-sized dome balanced on top and then a small dome on top of that. ‘Home!’ he declares, standing back proudly.

‘Home?’ I say doubtfully. It looks kind of like a jelly.

Then I look at his picture again, and suddenly I get it. I can see exactly what he’s drawn: it’s the Spirit Stone, on the top of the mound, at the top of the hill. ‘Home!’ I say, tapping his picture with my finger and laughing out loud. ‘I know exactly where your home is! We call it “home” in my forest too! Look, Harby!’ I point across the valley; the massive moon has risen so that it looks like it’s balanced right on the topmost tip of the Spirit Stone, like a ball on a circus seal’s nose. ‘It’s the Spirit Stone! Home!’

‘Home?’ says Harby, squinting into the darkness, not seeing it because he’s forgotten it’s there.

An idea strikes me then; I think about what Mum always says to Dad when he loses his keys: retrace your steps.

Maybe that’s what I need to do too: I lost my way over there, on the Spirit Stone side of the valley, somewhere between Gabriel’s Oak and the river … That’s where it must be … the portal … or the magic gateway … or whatever manner of craziness took me from my Mandel Forest to this Stone Age one.