It was morning when I last had one of these dreams, but this time the sun is beginning to set.

Aminah laughs. ‘Maybe,’ she retorts. ‘I was beginning to think I’d imagined you.’

The girl looks at her quizzically.

‘From the other day?’ Aminah continues. She seems a little embarrassed. ‘I called out to you as you were climbing back over . . .’ She lets her words fizzle out.

The girl’s eyes widen. ‘It was you? I’ve been avoiding this place because I thought some stupid little kid started playing here.’

The pair settle beneath a tree, and I join them. From down here the wall that leads back to Aminah’s house looks giant, like a skyscraper, and the trees just as tall. I can no longer see either end of it. Instead I’m surrounded by a canopy of leaves and sand, like being marooned on some sort of desert island.

Everything here is strange, ever-changing. Before Aminah and the girl appeared it was just a plain old wall with some sand on the ground. Now it’s like a secret garden. Suddenly I feel so tiny, in a big, big world, the way I always do when I play Fairy Hunters.

One minute you’re casting spells against a wizard, the next you’re hit with a shrink potion and you’re the size of a mouse. And, all of a sudden, your perspective shifts.

The cat I had followed sits a few metres away next to a smaller cat that looks identical. But even they’re different here. Bigger, wilder.

Aminah scowls. ‘I’m not a child! It was probably my sister you heard.’

‘So, what’s your speciality?’ the girl asks, changing the subject at lightning speed.

Aminah frowns. ‘What?’

‘You know, if you’re an assassin?’

The sun’s almost gone now, and the girl pulls a torch from her backpack, setting it out between us all. It lights up the circle like a magic orb, but everything surrounding us is coated in inky darkness – apart from the two pairs of feline eyes that stare from the bushes.

‘Oh, yes, right!’ Aminah says, biting her lip, as if in contemplation.

‘Mine’s a bow and arrow,’ the girl says, answering her own question. ‘That way I can watch my victims from a distance.’

‘Remind me never to come back here before you do, so you can’t ambush me.’

‘Who says you’re allowed back?’

Aminah raises her eyebrows. ‘It’s behind my house, isn’t it?’

‘Mine too,’ the girl says dismissively, pointing at her own home. You can just about see the top of the roof from here; it looks like a castle turret. ‘And anyway, I found it first.’

‘What is this place?’ Aminah looks around in wonder the way I had moments before.

‘A secret,’ the girl says simply. Then she adds with a smile, ‘I’ll let you back if you pass the test.’