You tell me you’ve got something to show me. Something about a monster. I trust you. God knows why I still do. All I wanted was a holiday where they had exotic fruit on the breakfast buffet, and we ended up here.

We scramble down a cliff. Feed ourselves into the darkness sideways through a space half the width of a door. To my surprise, the rocks drop off immediately inside, and I almost fall on my hands when I land, knee-deep in cold water. I sneeze. Perhaps it’s some kind of evolutionary response. Or allergies, yes, that’s more likely. I’m allergic to this place.

“You could have told me,” I spit, breathlessly. I can’t see where you are, so I direct my frustration at the water, and my inappropriate wellies. There’s a pain shooting through my ankle.

My eyes adjust to the dark and I realise I’m standing in a cave. Way up where the dank space ends, by the quivering light of my head torch, there’s a sheen to the rock, the colour of rose gold. Thirty feet from me, the pool ends in a gravel beach, where my wife is standing. She is consulting the map, if I can call it that. It looks like a page out of a three-year-old’s colouring book.

“It’s this way,” she says, and she points to where the cave narrows. “The passage. Coming?”

I stand there, cold and miserable in the half-dark. My ankle is throbbing and I’m worried it will swell up and I won’t be able to get my wellie boot off, and there’s a good chance I’ll get DVT and end up dying down here, and my mother won’t even have a body to bury.

“No,” I say, as decisively as I can. In the echoing space, it sounds petulant.

“What’s wrong?”

“I – I thought Tresco would be relaxing. I dunno. More like Monaco,” I protest.

“Oh, you mean, why are we down here?”

“Not just this. The camping. The cold. The cartons of juice.”

“You’re not having a good time?”

“We haven’t even had a cream tea, Julie. And I really need a sit down.”

“Is your foot alright, Max?”

I look down. The water I’m standing in is a deep red. It’s creeping to the edges of the pool. I can smell tin.

“It’s the monster, Julie,” I say, weakly. “It’s got me.”