It was raining. We’re buried in a leaking pipe and it’s raining. Which means water is soaking through the ground to fill the pipe up and drown us.

‘Wait a minute, wait a minute,’ I say. ‘The pipe probably won’t let in large amounts of water. We just need to keep calm.’

But, as Kay pointed out, there must be some pretty sizable holes in the pipe. And there are already puddles forming. We need to find the exit as soon as possible.

‘Just keep moving,’ I say. ‘Everything will be all right, if we just keep moving.’

But a few minutes later it’s clear that everything is not all right. The occasional puddles have joined to make a stream around our knees.

‘When you say raining . . .?’ I ask.

‘Big raining. Hard. Lots.’

But, it doesn’t make sense. Somehow there is a serious amount of water filling up this pipe. ‘It can’t just be what’s seeping through the earth.’

‘You’re saying it can’t, but it is. It’s coming.’

I’m balancing on a narrow edge. I could very easily tip into hysteria. ‘We’ve got to move faster.’ My voice sounds like it’s coming from someone else.

Crawling quickly is hard. I’m shivering and my trousers are soaking. The cables make the surface of the pipe uneven. My knees are killing me. My back aches so much that every movement sends a wave of pain like burning needles up my spine.

We stop talking and there’s only the pathetic sound of us sloshing along in the dark.

‘Blake?’ Kay says in a tiny voice.

‘What is it?’

‘I don’t know how to do that thing to stop you going down in the water.’

My heart contracts. Poor Kay. I can’t even begin to tell her that it’s not swimming that we need to worry about. The water is over my wrists now. ‘It’s okay,’ I say. ‘I can swim. I’ll help you. We’re going to get out of here.’

But the further we go the more convinced I am we’re trapped. I pray that the water has levelled off, but after a while I know that it’s still creeping up my forearms. I close my eyes and listen to the constant dripping of water. I’m so cold yet my knees are on fire. We go on and on and on. Imprisoned in the earth. A scream tries to claw its way up my throat. I force myself to swallow.

Eventually, Kay says, ‘Can you see that?’

I open my eyes. The water is over my elbows now. Fuzzy spots are floating in front of me. I can’t see anything. ‘What?’

‘It’s more lighter.’

It’s a while before I think she might be right. But then I can definitely make out the dark outline of Kay in front of me.

‘It is! It’s lighter. We’re getting to the end,’ Kay says.

If there’s a light, then that means a way out. Back into the open, out of this suffocating plastic tomb. My arm muscles are twitching with exhaustion, but we hurry towards the light. Soon I can see Kay more clearly. The water still looks black and has reached her hips.

‘Can you see anything?’ I ask.

‘I don’t know. Wait . . .’

The light seems to be coming from above. Kay stops. ‘It goes up,’ she says.

I lean to the side to look past her. The pipe makes an abrupt corner turning upwards. Horror jolts through me. If the pipe continues straight up, how on earth will we climb it?

‘Where does the pipe go?’ Kay asks.

I can’t speak. I squeeze past her and push upwards into the bend. My legs shake as I stand. Straight away, I can see the circle of light above me that is our exit. It’s within reaching distance.

It’s also covered in bars.