Now that Gram has left for work (I ‘suddenly remembered’ a Geography assignment that I hadn’t finished, so she left without me), I have chugged another two cups of what I now think of as Dr Chang’s Fantastically Foul His Skin So Clear.

I am getting better at keeping it down. I am not feeling sick so much, although my stomach is churning with nerves and is distended with gas, just like the last time.

I figure I will wait for the gas to start to make its escape, as it were, before I get on the sunbed. I want everything to be the same as before.

I don’t have to wait long. An hour or so after Gram has left, I start on the burping.

I’m trying to back-time from the start of our school Whitley’s Got Talent show, which is 1.30, straight after lunch. Last time, my invisibility lasted about five hours, so really I don’t want to get off the sunbed till about 10.30 or later. That means that, so far, my timing is fine.

My heart is beating, my stomach is twisting, my brain is racing, and as for my burps – you just don’t want to know. This is not a normal smell. Even if you’d been eating curried eggs or something, you could not produce a smell like this. It hangs in the air of the garage like a toxic fog.

Getting on the sunbed this time is different from the last – mainly because I know what is going to happen, so I am nervous, and also I won’t fall asleep. Instead, I just lie there, with my eyes shut.

I’ve put the radio on this time, and a caller to the radio station is saying:

‘… so I’d like you to play “Light the Light” by Felina for me please, Jamie.’

That’s strange. I mean, I know it’s just a coincidence, but still …

‘Great choice! Great choice. One of my personal favourites. Why that one, Chrissie?’

‘It’s for my mum,’ says the caller. ‘It reminds me of her. She passed away when—’

But Jamie Farrow cuts her off, presumably because nine thirty in the morning is no time to be getting maudlin on Radio North-East.

‘For your mum! That’s lovely, Chrissie, what a nice thought, and I’m sure she appreciates it wherever she is. So, for Chrissie in Blaydon, and her lovely mum, here she is: the late, great Felina with “Light the Light”.’

The song is already familiar to me: the slow boom boom boom of the bass drum to start, then a deep, rusty guitar chord followed by Felina’s throaty vocals, and for some reason – no doubt the combination of the fear I’m feeling and everything else that’s happening – I find myself getting emotional. A lump appears in my throat, which I swallow back down, and I have to turn the radio off.

I lie in silence and let the time drift by, and I close my eyes because it’s not good to stare at the UV tubes inside a sunbed.

I know I don’t fall asleep, but it’s like waking up. I know it’s happening, because the UV light starts coming through my eyelids, slowly at first.

I open my eyes to take a look at what’s happening.

Holding my hand in front of my face, I can see through it: it’s like it’s made of a translucent plastic, getting clearer by the second. It’s hard to see precisely, because my eyes are a little bit dazzled by the strong light, but it is definitely, definitely working.

I know it is finished when I close my eyes tight and I am still looking at the mauvey light of the sunbed tubes.

To be on the safe side – although I’m not sure if ‘safe’ is the right word here – I lie there for an extra few minutes before lifting the lid and climbing off.

I go over to the mirror and marvel once again that I am totally, utterly, amazingly invisible.

And now I’m going into school.