This whole thing – the breaking and entering, plus robbery, arson, stealing a moped and killing someone (sort of, anyway), not to mention time travel – started on my twelfth birthday.

That day, I got a hamster, and a letter from my dead dad.

I suppose, if you were being precise – and precision, as Grandpa Byron says, is everything – it started when me and Mum moved in with Steve and The Stepsister From Hell, Carly. That was just after Mum and Steve got married in the world’s smallest wedding (people there: Mum, Steve, Grandpa Byron, me, TSFH, Aunty Ellie.)

If you were being super-precise, it kind of started when Dad died, but that was a long time ago and I don’t really want to get into that. Not yet, anyway.

So there we were, on my twelfth birthday, which is May 12th, so I was twelve on the twelfth, which only happens once in anyone’s life, and some people have to wait until they’re thirty-one by which time I guess it’s not so much fun.

Steve is always trying to make me like him so he spent a lot of money on my present, a replica Newcastle United shirt with my name and age on the back: “Albert 12”. Except my name’s now Al, not Albert, and I don’t really like football. I’ve sat and watched a few games with him, because it makes Mum happy to see us ‘bonding’, but to be honest I don’t really see the point of the whole thing.

“Well, put it on, Al – see if it fits!” says Mum, and she’s smiling this too-smiley smile, and I’m smiling too to make up for the fact that I don’t like the present, even though I know it’s kind of him, and Steve’s smiling a sort of puzzled smile, and about the only one smiling properly is Carly, probably because she can tell I don’t like the present and that makes her happy.

It’s on the big side, so no chance I’ll grow out of it soon, which is a shame.

Mum’s present is much better. It’s there on the countertop: a big box, wrapped up in coloured paper, with a ribbon and a bow, just like presents look in drawings, and I have no idea what it is until I unwrap it and the box inside says ‘Hamsterdam – The City For Your Hamster’. There’s a picture on it of tubes and boxes and a cage and everything, and I’m grinning so hard because I have guessed what’s in the small box that Mum’s holding, and sure enough there’s a hamster in there – a cute, small one that’s not fully grown yet, and he (or she, I don’t know how to tell yet) has got this twitchy nose and light brown fur and I love him (or her) already.

I’m wondering what to call him, when Steve says, “I’ve got a great name for him!”

“Steve,” says Mum, “let the boy choose his own name.”

Steve looks a bit disappointed, so I say, “It’s OK. What’s your idea?”

“Alan Shearer!” Steve sees me blinking, blank-faced, so he repeats: “Alan Shearer. Greatest striker the toon ever had? Premier League’s all-time top scorer?” I still look blank. “Bloke on Match Of the Day?”

I nod and force a smile, but as I’m doing so, it kind of turns into a real one, because whichever way you look at it, giving a hamster a proper name like ‘Alan Shearer’ has got to be better than ‘Fluffy’ or ‘Hammy’ which was as far as my imagination had got. So Alan Shearer it is.

I notice that Carly has stopped smiling. She comes over to me as I’m unpacking the plastic tubes and bends down close so that only I can hear. “A hamster?” she murmurs. “They’re just rats for babies.”

You know what, though? I don’t care.

Then Grandpa Byron arrives to give me a ride to school like he always does since Mum and I moved further away to live with Steve and Carly.

I open the front door and he’s standing there in his long saffron-coloured robes, grey hair in a braided plait, little round sunglasses and huge biker boots. Under one arm, the bad one, he’s holding his motorbike helmet, and in the other, the good one, is a birthday card in an envelope.

“Happy birthday, bonny lad,” he says, and I give him a huge hug. I love Grandpa Byron’s smell. It’s a mixture of the minty oil that he puts in his hair and these sweet-smelling cigarettes he sometimes smokes called beedis that he buys in boxes from a man who runs a Lebanese takeaway, even though he’s from Bangladesh, and the liquorice-flavoured toothpaste he uses, which I have tried and is pretty gross, but it smells nice.

As I hug him I take a deep breath. He waves through to the kitchen, which isn’t far from the front door. “Morning, Byron!” calls Mum. “Come on in!”

Carly shimmies past me to go up the stairs. “Hi, Byron,” she says, sweetly. “Lovin’ the robes, dude!” It’s only when she has passed him and is out of his sight that she turns to me, wrinkles up her face and wafts her hand in front of her nose, as if Grandpa Byron’s smell is something bad, which it totally isn’t.

He’s got a funny way of talking, my grandpa: his Indian accent sounds Geordie and he uses Geordie expressions and old dialect words all mixed up together. He’s my dad’s dad, but my dad didn’t really talk Geordie, not much.

Grandpa comes in and sits at the breakfast bar. “Sorry, mate – I wasn’t having a chance to get your present.” He wobbles his head in that Indian way, probably just because he knows it makes me laugh, and he’s smiling as he does it so I can see his big gold tooth.

“S’OK,” I reassure him, and I open the card. Out fall two twenty-pound notes.

“Thanks. Thanks a lot!” And I really mean it.

Then Mum says, “I’m glad you’re here, Byron. It’s time to give Al the letter,” and she gets up and goes over to a drawer. She’s behaving a bit strangely, like flighty and excited and nervous when she skips back with this big fat envelope. Steve’s watching her, smiling quietly, but it’s clear from Grandpa Byron’s face that he hasn’t got a clue what this is about. Mum puts on her serious face.

“Now, Al. This is for you, from your dad.”

I don’t know what to say.

“We found this in your dad’s things after he died. He must have written it ages ago.”

I’m staring at the envelope in her hands. Grandpa Byron’s expression hasn’t changed.

“What is it?” I say eventually.

“I don’t know. It’s personal, addressed to you. But I think you should regard it as highly private –” and here she pauses – “not to be shared with anyone else.”

I take the envelope carefully and read the spidery writing on the front. My dad’s handwriting, and my full name: Albert Einstein Hawking Chaudhury. Below my name is written: IMPORTANT: Do NOT open this envelope until SIXTEEN hours after receiving it. To be delivered on his twelfth birthday.

I look across to Grandpa Byron. “Did you know about this?” I ask.

He shakes his head, and there’s something in the quick side-to-side movement and the tightness of his mouth that is odd. I even think he’s turned a bit pale, and he’s staring at the envelope.

Steve, meanwhile, is just sitting there with this big daft smile that looks slightly forced and I get straight away that he’s jealous. He wants so much for me to like him that he’s angry that my dad has come back between us, and this makes me like Steve just a little bit less.

“Well, I can’t open it till later anyway,” I say, pointing at the instructions on the envelope. Now obviously I’m boiling inside to see what it says, but there’s something about seeing my dad’s handwriting that’s like getting an instruction directly from him, and I want to be respectful. That, and Grandpa Byron’s stony face, has kind of freaked me out.

“Ha’way, son, you gonna be late,” he says, picking up his helmet from the breakfast bar. And that is the last thing he says to me until he drops me at the school gate, saying, “You coming round after school?”

I nod, and he scoots off on his bike, not even waving.

All of which makes it a very unusual morning.