I jumped down, shoving in one of the curtains, and then another one. I reached over for the first can of petrol, carefully soaking all of the material.

There was another sudden whisk of cold air above us as the tentacle came back. We both ducked sharply, and for a minute it felt like I wanted to stay there, hunched inside the Jellyfish.

‘Quick,’ said James, and I could hear that he was panting with fear.

I grabbed the rest of the curtains and threw them down.

‘Keep low,’ I said.

The vibrations beneath us had turned to a rumbling menace that made even the petrol cans vibrate.

‘Get out of the way,’ I said to James as I started pouring two cans of petrol over the curtains. He grabbed another couple.

Thwack! The ground shook as a tentacle smashed on to the mesoglea next to us.

We crouched down further in the pit. I undid all of the lids on the cans and tipped them so that they sloshed down on to the material. There was a pool of petrol covering the curtains now, and we were both having to clutch on to the mesoglea, exposing ourselves to the flailing tentacles, in order to avoid getting it on our shoes. I had the final can ready.

‘Go,’ I said. ‘Go back to the boat.’

‘What?’

‘Go now.’

He paused.

‘Trust me! Wait for me there, but get the oars ready.’

He ran. Keeping low, and still clutching his machete.

There was another sudden thwack behind me, and the ground shook again.

I pulled the rope out from the can quickly, splashes of petrol coming with it and soaking into my jeans.

There was another whooshing of wind from overhead. There was no time for thinking. I grabbed a shovel and quickly tied one end of the rope around it. Then I threw it into the petrol pool. It disappeared beneath the liquid.

I waited for the tentacles to do another swoop, and then I ran towards the boat, unfurling the petrol-soaked rope behind me. Beneath my feet, the mesoglea was roiling and rippling with urgency and confusion.

James was lying down in the boat, trying to avoid the rage of the Jellyfish, but we didn’t have much longer. I leapt in, pulling out the box of matches from my back pocket. I was covered in petrol but, right then, being burnt alive seemed like a less painful way to die than being whipped across the sea by a giant tentacle.

Dropping my end of the rope on to the mesoglea, I lit a match and threw it. The rope went up immediately, a trail of flame leading towards the centre of the creature.

‘Give me your machete,’ I said.

The Jellyfish seemed suddenly to sense what we were doing, seemed suddenly to realize.

There was a brief lull, and the vibrations stopped, the tentacles paused in mid-air.

‘Get ready,’ I said.