“Happy birthday, Maisie!”

With a broad smile on her face, Mum slides a pile of envelopes across the kitchen table towards me. Behind her, Dad glances over his shoulder with a grin, still keeping one eye fixed on the banana pancake that’s cooking in the frying pan. The molecules that make its sticky-sweet smell weave their way from the stove to the odour receptors in my nose, making my stomach rumble in anticipation.

“Thanks, Mum,” I say, looking down at the oversized envelope at the top of the pile. I recognise Mum’s handwriting straight away, my name written in large letters across the silver envelope.

Maisie

“Go on,” Mum says. “Open it.”

As I turn the envelope over, I can see that it’s kind of lumpy in one corner and instantly realise what this means. Trying to keep a smile on my face, I rip the envelope open and pull out an enormous birthday card.

On the front, there’s a picture of a space rocket zooming through a starry sky, the constellations arranged to spell out the words HAPPY BIRTHDAY. And fixed to the top corner is a bright-blue badge with a big number ten printed inside a star.

Ignoring the badge, I quickly open the card, trying not to blush as I read the message inside.

To Maisie

Hope your birthday is out of this world!

We’re so proud of you. Have a fantastic day.
All our love,
Mum and Dad
xxx

Mum looks at me hopefully as I set the card on the table.

“I took ages choosing it. So many of these birthday cards for girls nowadays have such silly stuff on them – glittery unicorns and fairies and things. I wanted to choose one that was just right for you. I do hope you like it, Maisie.”

I nod my head, even though the constellations aren’t exactly astronomically accurate.

“It’s perfect, Mum. Thanks.”

“I wasn’t sure about the badge. Ten’s not too old for a badge, is it?”

“Stop fussing, Laura,” Dad says, leaning across the table to slide a banana pancake on to my plate. I look up at him with a grateful smile. “Maisie doesn’t mind what her card looks like – it’s the birthday presents that she’s waiting for.”

As the banana pancake smell hits my nostrils in full effect, I feel an adrenalin rush of excitement at Dad’s mention of my birthday presents.

It’s true. I don’t mind that Mum’s got me a birthday card with a badge, even though they’re really just for little kids. If Mum and Dad have got me the present that I’ve set my heart on, I’ll forgive them anything.

I’ve dropped loads of hints, leaving copies of New Scientist open on the kitchen table and pinning up articles to the fridge. I know they said they couldn’t afford to spend a bomb on my birthday present, but I hope Mum and Dad have got me the kit I need to help me build my own nuclear reactor.

It all started when I watched this documentary about this American kid who built a nuclear reactor in his garage when he was a teenager and this kind of inspired me. Now I’m planning to be the first person in the world to crack the power of cold fusion.

When I first told Mum and Dad that I wanted to build a nuclear reactor they kind of freaked out, worrying about radioactive waste and stuff like that. Dad said he liked the fact I was getting interested in sustainable energy, but he didn’t want me blowing up the house.

I told Dad he didn’t have to worry. You see, most nuclear reactors work by splitting atoms. This is called nuclear fission and releases a huge amount of energy in the form of heat. Inside a normal nuclear reactor, the temperature can reach over 300º Celsius. That’s hot enough to melt lead!

And then there’s nuclear fusion, which is even hotter. Take a look up at the Sun. All the light you can see, all the heat that you feel is being produced deep inside the Sun when smaller hydrogen atoms fuse together to create larger helium atoms. The energy that this releases is what powers the Sun and every star in the sky.

When I explained all this to Dad I could see that he was starting to get really worried, so I quickly explained that the kind of nuclear reactor I was planning to build was completely different. Cold fusion does what it says on the tin. Nuclear reactions at room temperature, not even hot enough to melt the butter in Dad’s frying pan. No radioactive waste, no chance of explosions. All the energy you need – totally safe and clean.

The only problem is nobody’s quite worked out how to make cold fusion work yet. Loads of scientists have tried, but recently I was reading about this experiment that NASA is building and it gave me a great idea. I drew Mum and Dad a diagram of my plans for a DIY reactor and explained how the cold fusion process using the weak nuclear force would be completely safe.

To be honest, I don’t think Mum and Dad really understood what I was telling them, but when I said that all I really wanted for my birthday was a backward wave oscillator, a hydrogen generator and fifty tubes of kitchen foil, they said they’d think about it.

That was four weeks ago and now it’s my birthday.

“Can I open my presents yet?” I ask eagerly.

“Not yet,” Dad laughs, retreating to the hob to ladle another dollop of batter into the pan. “Eat your breakfast first. And you’ve got the rest of your birthday cards to open yet too.”

With a grin, I squirt a trail of golden syrup across my pancake. If Mum and Dad have got me what I need, I might be able to harness the power of a star in the old freezer in the garage.

I’m just taking my first mouthful of pancake and thinking about how I’ll be able to hook up the hydrogen generator when the door bangs open, causing Mum to jump halfway out of her chair.

Lily flounces into the kitchen. She’s wearing a long-sleeved T-shirt that almost reaches her knees, a picture of some eighties pop star printed on the front.

“Morning, Lily,” Dad says, giving the frying pan a shake. “Fancy a pancake?”

Then he does a double-take as he notices what she’s wearing.

“Is that my Cure T-shirt?”

Lily frowns as she flops down in the chair next to mine.

“I borrowed it,” she says, fiddling with the hem of one of the sleeves. She tugs it down over her wrist. “I didn’t think you’d mind.”

“I don’t,” Dad replies with a shake of his head. Picking up a spatula, he flips over the pancake that’s starting to sizzle in the pan. “But maybe ask next time, OK?”

Lily sighs with a roll of her eyes. Then she turns towards me and pushes an envelope across the table.

“Happy birthday, sis.”

“Thanks, Lily,” I say, feeling kind of surprised. “I didn’t think that you’d remember.”

“Well, it was kind of difficult to ignore with everyone going on about it all the time,” Lily replies. “I mean, you’d think you were the first person in this family to hit double figures with the fuss that everyone’s been making.”

“That’s not true, Lily,” Mum says, reaching out to rest her hand on top of Lily’s arm.

“It is,” Lily insists, her voice almost pained as she snatches her arm away. I watch the smile on Mum’s face crack a little. “I never had any of this for my tenth birthday,” she says, gesturing towards the patio doors through which the poles and plastic sheets for the gazebo can be seen laid out across the lawn. “You just took me and my friends to see some stupid cartoon at the cinema.”

“That was different,” Mum says, keeping her voice calm even as her rejected hand trembles in mid-air. “You wanted to do something with your friends on your birthday, but Maisie…”

Mum’s voice trails away. It’s OK. She doesn’t need to say it because I know the rest of the sentence anyway. I don’t have any friends.

The only people coming to my party today are members of my own family. Mum, Dad and Lily, Nanna Day and her friend Elsie, Aunt Maggie, Uncle Colin, Auntie Pat, Grace and Jack, all my other aunties and uncles and the rest of my cousins too, even baby Alfie. All ages from eight months to eighty years old, but there’s only going to be one person who’s ten and that’s me.

You see, because I don’t go to school, I don’t have a ready-made gang of friends like Lily. She’s always going round to her best friend Sophie’s house or inviting Sophie, Daisy and the rest of her friends round to ours. They stay up in Lily’s bedroom for hours on end. They’re supposed to be revising for their GCSEs, but seem to spend most of their time OMG-ing at the tops of their voices.

Sometimes I hang round the bottom of the stairs trying to work out what they’re actually doing up there. But I can never quite hear what they’re talking about, just the occasional boy’s name mixed in with squeals of excitement.

And when Mum sends me upstairs to ask if they want a biscuit or a drink, Lily always gives me the dead-eye – the room going instantly quiet as soon as I walk in.

I used to think Lily’s best friend Sophie was nice. She always used to talk to me when I went up to Lily’s room. Sometimes I even started to think that she could be my friend too.

What used to happen was Sophie would grab hold of her revision textbook and flick to the answer section at the back. Then she’d fire questions at me and everyone would cheer when I got them right – everyone except for Lily. How old is the universe? Which fossil fuel produces the most carbon dioxide? What speed does electromagnetic radiation travel in a vacuum? It wasn’t a big deal. They were only simple questions. But it still felt kind of special to have the chance to hang out with Lily’s friends, even if it was just for a little while. I thought Sophie liked me.

But then, one time, I hung outside Lily’s door for too long when Mum had sent me upstairs with the biscuits and the drinks.

“Oh my God, Lily,” I heard Sophie say, the sound of her voice squeezing through the half-closed door. “Your little sister is such a freak. She’s practically autistic.”

I stood there at the top of the stairs, the mugs of tea and a plate piled with chocolate biscuits trembling on the tray as I waited for Lily’s reply.

I don’t know what I wanted her to say. To stick up for me, I suppose. To tell Sophie that I wasn’t a freak. There’s nothing wrong with being autistic, but I’m just academically gifted. But my sister didn’t say a thing.

I left the tray at the top of the stairs. Mum didn’t make me go up to Lily’s room after that.

So this is why Mum and Dad have invited the whole family to my birthday party. They think it will help me forget that I don’t have any friends.

“Never mind whose tenth birthday was the best,” Dad says, trying to keep the peace just like he always does. He slides the latest pancake out of the frying pan and on to the plate in front of Lily. “Have a banana pancake.”

Lily curls her lip as she inspects Dad’s culinary creation. I’ve only just started mine, but I already want another one. They’re just so delicious.

“I don’t want a banana pancake,” Lily says, pushing the plate away. “I just need some toast and a coffee.”

Dad looks kind of hurt. Banana pancakes are his speciality.

“Are you sure?” he asks. “Do you know that bananas are the perfect brain food? It’s something to do with all the albino acids they’ve got inside them.”

I think Dad’s been reading my New Scientist again. He might be a whizz when it comes to technology, but he doesn’t know the first thing about biology.

“Amino acids,” I say.

“That’s right, amino acids,” Dad agrees. “It said so in one of Maisie’s magazines. Apparently these amino acids can boost your brain function and even stop you from getting stressed.” He gently pushes the plate back towards Lily. “Your GCSEs are just round the corner. Why don’t you try a bit of banana pancake? It might help.”

Actually I think New Scientist said it was the magnesium in bananas that reduces stress, but before I can tell Dad this Lily just explodes.

“You’re the one making me stressed,” she says, spitting out the words as she pushes her chair back with a screech. “Going on about my GCSEs when I’ve just got out of bed. I only wanted a bloody piece of toast.”

“Lily!” Mum says.

But my sister just springs out of her seat.

“Don’t you see? It doesn’t matter how many banana pancakes I eat for breakfast,” she shouts, crossing the kitchen in a handful of strides. “I’ll never be as clever as Maisie.”

Storming out of the room, Lily slams the door shut behind her.

Mum and Dad stare at each other in shock as the sound reverberates around the house.

It might be my birthday, but as usual Lily’s managed to make it all about her.