I can hear the tiny deckchairs dancing around inside the tin and I’d really like to take them straight to the little town lock-up, which we agreed would be the safest place for them. It’s not a prison any more, it’s a tourist attraction, but it does have iron bars and a letter box and nothing inside. And Grandma has a key.

But we need to wait until dark, and we need to take a look inside the cave at the end of the beach.

The last of the holidaymakers are leaving, and Eric, Jacob and I try to look as if we’re beachcombing.

I don’t really get beachcombing – it’s all rubbish, some of it’s bone rubbish and some of it’s plastic rubbish – but I try to be convincing.

The mayor’s daughters climb out of the pedalo, rubbing their legs. He greets them on the shore and the larger one shouts something at him and waves her arms violently, which I imagine means something like I’m not doing that any more.

With a miserable face, the mayor drags the pedalo back up the beach and leaves it chained to the wall. He doesn’t put it in the cave.

The remains of some of the sculptures are still visible on the beach. A sand dragon that has lost its head and half a mermaid, between all the flattened patches and new sandcastles. Jacob kicks the head from the mermaid, tramples the dragon flat and knocks down the largest castle. He’s very similar to a windbreak at times.

Albert Fogg drags the last deckchairs towards the cave and I pretend to examine a really interesting pile of bladderwrack. Eric joins me. ‘See,’ I say. ‘Over there.’ I point towards the door in the side of the sea wall.

We crouch on the beach, watching and waiting. Albert Fogg rummages in his overalls for a key.

‘What’s he doing?’ asks Jacob, arriving panting behind us.

‘Quick,’ I say, ‘let’s get a look inside.’

We stroll and then gallop until we’re close enough to see, but far enough away for Mr Fogg not to notice us.

The door swings open and he shines a torch through the opening. I can’t see exactly what’s going on, but things are moving inside.

‘Did you see that?’ I say to Eric.

He nods.

Albert Fogg arms himself with a broom and goes in bellowing. ‘Get back, you nasty things, you. Get BACK!’ There’s a crack and bang and Mr Fogg rushes out clutching his elbow. He tries to shut the door but a windbreak jams itself in the hinge and he can’t.

‘You beastly things, get back – or I’ll destroy the lot of you.’ The beach equipment inside his store doesn’t seem to be able to hear and starts to stagger onto the beach.

‘Help!’ he yells, slipping backwards as a huge deckchair with an extra leg-rest topples towards him.

I get there just as the cloth of the deckchair starts to smother his face. ‘Pull,’ I shout to Eric, and we both grab the leg-rest end and tug violently until Mr Fogg struggles free from underneath.

The deckchair joins its brothers stamping out of the cave and standing on their ends on the beach.

Jacob dances back and forth in front of them looking big, his eyes flashing dangerously red.

More and more of the chairs march out of the store, until they’re five deep on the beach, and then the first one finds the steps at the back and tries to climb them.

We watch in horror as it manages to get halfway up towards the promenade.

‘Oh no,’ says Mr Fogg, sinking his face into his hands and moaning. ‘I’m done for,’ he says, collapsing onto the beach and pulling his coat up over his head.

I check the beach – it’s empty – and Mr Fogg can’t see, so I wave at Jacob and he lets loose a long tongue of flame, which bounces across the deckchairs, crackling, singeing and sparking, but not really burning.

The chair on the steps pauses.

‘Again,’ shouts Eric, already beginning to drip from his fingertips.

The heat is immense as Jacob sends lightning bolt after lightning bolt at the chairs, and then Eric counters this by sprinkling them with water. A wall of steam rises from the beach and the chairs stop, evidently confused and hopefully intimidated.

‘I can shrink them,’ I say. ‘But it won’t really help.’

‘We can burn them this time,’ says Jacob. ‘They’re not a bit cute.’

‘They’re still living beings, and they’re Mr Fogg’s deckchairs,’ says Eric. ‘They’re his livelihood.’

The deckchairs stand facing us. Shuffling. Waiting.

Mr Fogg is still sitting on the beach, his face hidden. Waiting as well.

And then, as if someone switched them off, the deckchairs sag to the sand, tumbling, flopping, leaning and ultimately lying just as deckchairs should, awkward and floppy.