I walk into physics just as Ms Hastings is handing out our tests. Ms Hastings gives me a young lady, you're late look. I give her a tell me about it and have you noticed I'm swimming in a pool of sweat look. Ms Hastings raises an eyebrow. I sit at my desk.

Ms Hastings lays our tests facedown. She does the regular threats: 'You must not look at anyone's work!' and 'Put away your phones!' and 'Your time starts now'.

We flip our pages over.

Turns out, I am ready for the test. My brain fires up and the neurons make my hand move and the formulas come out like good little ponies at a show.

Most of my tests are fairly easy, which isn't me boasting; it's just a statement of fact. Mum says I might have a photographic memory, which is good for Mum because she often forgets her pin numbers and passwords.

Mum could be right. All I have to do is look at something and it sticks. Sometimes, the image repeatrepeatrepeatrepeats, like a GIF I can't turn off.

The room fills with the buzz of numbers. Pi scuttles over our papers, theorems talk to themselves. Ms Hastings looks at her phone—probably at some friend skydiving or snorkelling in the Bahamas, while she's trapped in here with us.

The bell rings.

'Time's up!' calls Ms Hastings. We hand in our tests. Next class is English.

I don't chat or dawdle in the corridors; I slip between the crowds, a fish weaving. In fifty-five minutes I'll have to speak to Grace. Just keep swimming, Biz.

Mr Birch stands like a flamingo in front of the class, one foot scratching the back of his leg.

'Okay, everyone,' he says, 'today we'll be writing about the ego. That is, your alter ego. Consider your readings over the weekend, and the work of Plath in this context.'

A collective groan from all of us. We've done Plath now for three long weeks and no one is a fan. I mean, we all 'feel' for her, but at this point we've read her and analysed her and discussed her and it's like peeling an onion until there's no onion left.

'I want you to write a description of your alter ego, due at the end of the day,' Mr Birch says, ignoring our protests. In case we don't remember what he's just said, he writes it on the whiteboard, his blue pen squeaking. He then sits at his chipped desk behind his PC, doing paperwork.

We hunker down to do the assignment. That is, some of us do the assignment; some of us daydream. The new boy pulls out a book and reads it behind his laptop screen.

Fans flick-flick above us. A trickle of sweat moves down between my boobs. I stare at my computer.

I don't much like to write about myself. It's not my thing, discussing any part of me. Over the years, Mum has suggested we go see people because Dad is dead, but then we put it off. I did sit with a man once, when I was seven and a half, in a room with yellow-painted walls and framed cat pictures. The man had round glasses like Harry Potter. He laid out paper and blunt colouring pencils and said to draw, so I did. Then he hummed and ha-ed and said, 'I'll just speak to your mum now, okay?' and when Mum came back out, her eyes were really red, so I didn't draw for anyone else after that.

The cursor blinks on, off.

I take a breath, and dive in.

My Alter Ego: A meditation/poem, by Elizabeth Grey

Consider the Ego / The ego is defined as a person's sense of self / Which includes but is not limited to self-esteem, self-worth and self-importance / Don't we all think ourselves important, that we matter? / We are matter, this part is true / But do we? / And / Is it possible to have an alter self / I.e.: an opposite, matterless self?

No / Such a thing cannot exist / The universe is made of matter / And if I am alter or other then I would be lacking matter or a sense of matter and as such cannot be in the universe / And if I am outside the universe, that makes me a singularity, a concept impossible to imagine / Therefore, my alter ego is beyond my capability for imagining / And thus, cannot be described.

The End

P.S. Some say God is a singularity, but people imagine God all the time / They think he looks like someone's white grandpa, or Santa Claus / God's Alter Ego is sometimes called a Dog / (Sorry) / It should be added that Dogs exist and have the potential to exist throughout the known universe / So it is possible that my earlier hypothesis is wrong.

I close my laptop, look up at Mr Birch, who'll get to read this masterpiece tonight. What a lucky guy!

The bell rings.

'Please email me your essays by midnight!' calls Mr Birch over the scrape of chairs, the shoving of laptops into bags, the clatter of our bodies beelining it to the door.

Now it's recess.

At recess and lunch, I always sit with Grace—and Evie and Stu and Miff and Rob and Sal. The Posse, they call themselves. I should say: We, as a collective, call ourselves The Posse. I am in The Posse. I am an integral member of The Posse, I think.

Grace and I have sat with The Posse since the first day of Year 9. We were both new. Evie saw us hovering uncertainly in the schoolyard, and decided we belonged to her. She brought us over to the bench under the tree by the fence. There, everyone interviewed us. What bands did we like? Did we prefer a day at the beach or inside? Had we read The Communist Manifesto? Had we seen One Flew Over the Cuckoo's Nest? Did we like it? Did we have a tattoo? If not, what would we get and where?

The group made the questions sound like conversation. But I could feel everyone marking us invisibly. Tick, tick, cross, tick, tick.

I let Grace answer first and watched everyone's faces. I crafted my answers the way their smiles went.

In the end it was okay. We could stay. But of course we could stay! The Posse is inclusive! The Posse is Love Incarnate!

We would have more people in The Posse, but most people are stupid, says Miff. We, The Posse, agree.

Before I came to this school, I was never in a group, so being in one—especially one with a name—was quite the novelty. It still is, because, I mean, I belong to six other people and they say they miss me when I'm not there. I've sat on the bench under the tree by the fence for just over two years now, laughing and saying things I think I'm supposed to.

And almost every second of every minute I'm with them, I feel like I'm seeing the scene from somewhere else. In front of a screen maybe, watching someone else's life.