2) Be home by three p.m. Sunday or I’ll come looking for you. (Seeing as Mum and Dad are supposed to be picking us up at four, this is pretty relaxed.)

3) Don’t do anything I wouldn’t do!!

Number three seems to be giving us permission to do absolutely anything we want because Grandad is a man with very poor risk-assessment skills. He once actively encouraged me to jump out of the cherry tree onto the trampoline, and he believes no hill is too steep to cycle down “if you’ve got the right attitude.”

“Grandad, are you saying we can climb tall trees?” I ask.

“Yes,” he says, nodding seriously.

“Have bonfires?”

“Of course! Have as many as you like.” (Grandad loves bonfires.)

Rose sees where I’m going with this. “Can I gallop fast on Orion, swim in the mermaid lagoon, and go to bed whenever I like, and possibly not at all?”

“Yes, yes, and YES!” Grandad laughs. “Just don’t run on the dragons. That’s dangerous. Oh, there is one last rule.” Grandad selects a new red chalk and writes:

4) Avoid all unnecessary winding up of Crowky—he’s unstable.

“Well, obviously,” says Rose. “Now can we go to Roar?”

“Yes!” says Grandad, and Rose is so happy that she does something totally unexpected: she throws her arms around me and gives me a hug.

Chapter 5

It doesn’t take us long to get ready. Grandad makes us eat some cheese and pickle sandwiches and then insists that we have a “journey pee.” Then Rose changes into her leopard-print onesie and I brush my teeth because I know it’s going to be a while before I see a toothbrush again.

We meet back in Grandad’s kitchen.

“Have you got the map, Arthur?” says Rose.

I pull it out of my back pocket. I’ve put it in one of those waterproof plastic wallets because we always get soaked in Roar. “But this is all we’re taking, right?” She nods and we start emptying our pockets into Grandad’s fruit bowl. Rose puts in her phone, some hairbands, and a fluffy Tic Tac, and I add a stubby pencil and some loose change. We’ve agreed to do this so we don’t leave any other “magical keys” behind in Roar.

“Please can you give this to Win,” says Grandad, holding out a package wrapped in a paper towel. “It’s rocky road. I told him about it when we were at his cave and he said he wanted to try some ‘so bad it hurt his brain.’”

“Sorry, we can’t take it,” I say.