The first of the locks fell on the mesoglea next to me. It was plaited at the bottom, from a long-ago attempt by Dr Jones to try and keep us looking neat. But the different strands in the plait had become so encrusted with salt and dirt that they had almost solidified, into something hard and spikey and impossible to separate.

‘Just shut up and cut,’ I said.

‘That sounds vile, anyway,’ said Lana. ‘You’ve never been into a women’s hair salon, have you?’

‘Nope. And sadly now, because of the apocalypse, I’ll never be able to.’ James gave a loud, fake-sad sigh, while another of my crusty pieces of hair fell.

‘I like my hair,’ he said. ‘I imagine it’s cool and good-looking.’

Me and Lana gave a loud laugh. I thought Kate gave a snort too, but it could also have been a cry-laugh.

‘You can imagine that if you want, but it isn’t what you look like,’ said Lana.

‘You do look good,’ I said. Lana raised her eyebrows at me. ‘I’m just being nice, Lana,’ I said to her, ‘but I think you might feel better if you cut them off, James.’

Another matted clump of hair fell. The air felt weirdly cool already against part of my head.

On the boat, nothing had changed. Soldier John, Stinky and Dr Jones still knelt, staring anxiously at the water. They were moving their arms and heads now, but their legs remained fixed rigidly. There was a muttering from the Jellyfish people.

Beneath us, there came a low, rumbling vibration. James paused in his hair-sawing, and Kate looked up. I think we all tensed, and I’m not sure I remembered to breathe. The tentacles were still swishing and waggling back and forth, to and fro, gently.

‘It must just be settling,’ I said.

‘Yeah,’ said Lana.

‘It’s checking we’re still here,’ said Kate. ‘That’s why it does that. That ripple, every so often.’ She kept her eyes fixed on the boat, which was still drifting slowly away. It was nearing the edge of the shorter tentacles now, to that calm patch of water above where the longer tentacles hide.

‘If that’s what it’s doing,’ I said, ‘then we’ve passed, haven’t we?’

‘Yes,’ said Kate. ‘They’re going to do it. They’re going to get to shore.’

‘Bollocks are they,’ said Lana.

Kate shrugged.