There is a television in the tech lab, which I have plugged in, and I’m watching the local news. On the screen are pictures of people on the seafront.

REPORTER: “Lifeboat-men and worried passers-by wait above the beach at Culvercot for news of a twelve-year-old boy still missing several hours after being swept out to sea. Named locally as Pythagoras Chaudhury, he and at least one friend were on top of the seawall this afternoon when it is thought they were hit by a massive wave. One boy was rescued about 500 metres from shore and was taken to North Tyneside General Hospital, where his condition is described as ‘critical’.”

DET. INSP. JOHN CALVERT: “We are very pleased at the rescue of one of the boys. He has been officially identified as Paul MacFaddyen, aged 13, from Culvercot. The search for Pythagoras Chaudhury was abandoned this evening as darkness fell and will resume in the morning.”

REPORTER: “Police say they would also like to talk to a third boy who was seen running from the scene shortly after the two boys entered the water. They stress he is not under any sort of suspicion, but need him to come forward to help establish what happened. The tragedy has prompted renewed calls from locals for a safety barrier to be erected along the top of the seawall. This is Jamie Bates in Culvercot for Tonight Live.”

I’m swallowing milk, cheese and custard creams and yoghurt, but every mouthful tastes of literally nothing. My stomach is getting fuller, and hurts less, but I just can’t taste the food. I feed bits of cheese to Alan Shearer and he twitches his whiskers, but it doesn’t make me smile like it usually does.

As well as being totally sad, I am totally scared, and I don’t know what to do.

I pushed Macca. People saw me. It’s not murder, because he’s not dead, at least not yet, but the police are definitely looking for me. They’ll want to know where I live, who my parents are. And as for Pye, well, barring some miracle, he has drowned. My dad is dead, and it’s my fault, pretty much.

Pye’s dad, Grandpa Byron, will want to know who I am, the boy who was – at any rate – involved in his son’s death, even if I didn’t actually kill him.

I can’t stay here in 1984, that’s for certain. I need to go back to my own time, and I must ensure that all traces of my time travelling are erased.

But is that even possible?

Assuming I could go back to my own time, what will happen when I get there? Will I exist? Can I exist? I have no father, after all.

If I’m to go back to my own time, I need the zinc tub which, at the moment, is still in the MacFaddyen’s bunker, and their house when I passed it at a distance earlier was swarming with people: reporters, sympathisers, police …

For a long time I just sit there, unblinking, my mouth turning sour from the cheese and milk I’ve been eating, and a pain in my chest, which could be from the running, and the tension, and Macca’s stamping, but which could just as easily be a broken heart.

It’s dark outside now and the sadness inside me is like the heaviness you feel when you’ve eaten too much and I feel breathless and exhausted. But one thing has changed: there’s now an idea in the back of my head.

Wearily, I turn on the six computers and then I head to the janitor’s store. There’s a stack of metal buckets. They’re made of zinc. They might just get me home.

I also need some matches, or a lighter. Surely in a janitor’s store there are matches or a lighter?

Not in this one.

It’s my dad who helps me out this time. Not his ghost, and not a time travelling version of him from some distant dimension. Just his voice, in my head, but it’s as clear as anything, like a voiceover track on a film. I’m wandering up and down the aisles of shelves, moving stuff in an increasingly frantic attempt to find anything that’ll create a flame, when I hear him.

“Shhh. Slow down, pal. There you go, easy does it. That’s what you need right there, it’s in front of you.”

I’ve stopped now, and I’m looking around me, trying to obey Dad’s soothing voice.

“No, there! In front of you.”

“The wire wool?” I say out loud, because I’m looking at a box of it – steel wool pads used for rust removal.

“Yes. You remember? In the kitchen?”

My breathing slows down and I remember every detail, and I close my eyes and I’m with Dad in the kitchen doing one of his mad experiments. I do remember, I do.

I smile, and grab a box of steel wool.