Grandpa Byron’s only been gone two minutes and I’m down the bottom of the garden in the shed where, in a different world, he kept his fireworks and Pye had his go-kart. If I had more time, I’d feel emotional, breathe in the smell of the shed and remember Pye and all of that.

But I don’t. I’ve just got to find a tin tub and all the way down the garden path I have been telling myself that there won’t be one, because there never is in situations like this, is there? You never find exactly what you’re looking for.

Except I do. At the back of the shed, filled with canisters of weedkiller and old plastic plant pots and bamboo canes, is a zinc tub and it’s huge. I can’t even feel jubilant owing to my nervousness. I’ve brought out all the rest of the stuff: the laptop, the back box, the cables, my memory stick, my hamster (of course), and in just a couple of minutes I’ve got it all rigged up, and the numbers are scrolling up on the screen faster and faster, and I’m beginning to feel a bit sick with anticipation and …

At this point I suppose I should tell you what my plan is.

It’s to go back One Last Time to 1984, to a few days before I last arrived, so that I won’t/can’t meet myself. I will then break into Pye’s shed and disable The Lean Mean Green Machine (I can’t destroy it, that would be heartbreaking, I’ll just take the wheels off or something), and then, to be doubly sure, I’ll go down to the slipway and move the stone and the supermarket trolley. That will prevent Pye’s first accident, and it should also prevent him from going out on the go-kart for a couple of days until he’s fixed it – just in case there is some weird ‘fate intervenes’ thing going on which means he’s going to steer his go-kart into the sea regardless. I tell you – I’ve thought of all of the possibilities.

That is, except for one thing that I suddenly notice.

The time machine seems to be losing power. The numbers have stopped scrolling, and the blurry film that once formed a big bubble-like dome over the zinc tub now looks a bit like a wobbly liquid surface coming halfway up the sides of the tub. There is, quite simply, no way I could possibly fit in there, let alone get back.

Should have thought of that. I tap the ESC button on the laptop, the program stops and I start to think this through.

After a moment, it comes to me. I won’t physically travel back in time, and I won’t personally move the brick and the shopping trolley. Instead, I’ll send my dad a letter telling him to do these things. And I’ll send it with Alan Shearer, so he doesn’t ignore it.

OK. A letter. This can work.

But then, as I keep thinking, a second problem arises, and this one’s even bigger.

A white cursor is blinking on the screen demanding that I input the string of letters that were written on the black box. The same black box that has been in and out of every dimension as well as my backpack, wearing off the pen marks. The writing on it is illegible. The string of letters now looks like this:

WM..GGGG...7..5E8... and then a big smudge containing a G.

WM … what came next? S? D? There were some numbers too. A three. A two?

I can’t remember the password.

Which means I can’t send a letter back to 1984.

I’ve left all the time machine stuff in the shed and I’m coming back up the path to the back of the house with Alan Shearer cupped in my hands, feeling totally defeated, when I hear Grandpa Byron’s moped buzzing up the front driveway. And something wonderful happens in my memory:

The sound of the moped makes me remember being on it earlier in the day, and how my bum hurt after fifteen miles …

And I was aching worst when we passed the road sign saying BLAYDON when we came into the town …

And remembering ‘Blaydon’ makes me think of the song, ‘The Blaydon Races’…

And whenever I think of the song now, I think of that rhyme to remember the Kings and Queens of England that Grandpa Byron taught me.

That’s the one that goes:

‘Willie, Willie, Harry, Steve,

Harry, Dick, John, Harry Three …

One, two, three Eds, Richard Two

Harrys four, five, six then who?’

It was the four G’s in the remaining smudged letters that made it click. “Geordie, Geordie, Geordie, Geordie, William and Victoria” was always my favourite line, and I knew now I had the password, starting halfway through on the chorus bit of the tune:

‘William and Mary, Anna Gloria

Geordie, Geordie, Geordie, Geordie, William and Victoria

Edward Seven’s next and then George the fifth in 1910

Edward Eight, then George, Liz Second.

Charlie Wills and George it’s reckoned!’

In other words: WMAG GGGGWV E7G5 E8GL2CWG

Imagine: I used to think of them as Grandpa Byron’s ‘memory tricks’, like they were something trivial.