Mr Flint, with his sweeping, glittering wings, is in a temper, his eyes glowing like coals. In fae ethics, everyone gets very intense about fae politics and the situation in the forest, and I try to keep my head down, but today’s lesson seems to be mostly about instilling fear, and Mr Flint is very good at that.

‘You are here to learn how to assimilate yourselves, not because it’s a party out there in the human world . . .’ He catches a couple of the kids chatting and raises his voice. ‘But because your own world is a battleground. So you will learn to assimilate. You will learn to hide your magic with your glamour. And you will go out there, and you will make a difference!’

‘And leave our families in Winterspell?’ Tash demands. ‘And do what? I don’t want to assimilate. There is nothing I need from the human world!’ She flashes her silver teeth.

‘Silly girl,’ he growls. ‘You need to survive. You need to learn how their world works so that you can help your family, and everybody who will remain in the forest. You have a choice! Not all do. The centaurs, the goblins, many of my troll brethren – they do not have the ability to glamour. They need the forest to remain. You must help to influence others in that vein.’

‘The forest isn’t under threat from humanity,’ Yanny says quietly. ‘It’s under threat from the shadows.’

‘And we will win that battle,’ Mr Flint says, slamming a hand down on the desk. It cracks and then folds like a pack of cards beneath his touch. His eyes glow. ‘There is no greater priority among the fae council. What you must do is survive it so that we all may survive the bigger fight: to keep the forest whole.’

Nobody answers this time, and Mr Flint’s anger has been burned out. He sighs down at the pile of rubble that was a desk a moment ago, and herds everybody into the adjoining room: a huge redbrick space with a high ceiling and polished wood floor, where the self-defence and spell-craft lessons are held. He’s filling in for the usual teacher today, and as his eyes flash around the room, I can tell he’s not going to make it easy for anybody.

‘So,’ he says, lifting himself to the wooden platform in the centre with a leathery flap of his wings. ‘Let’s see what you have been learning with Ms Elder. Tash and Stella – come on.’

My skin flares as Tash turns her silver eyes on me, mounting the platform with a nimble leap. I follow, using my hands to pull myself up and clambering on, knee-first. By the time I’ve picked myself up, she’s standing, feet planted wide, and of course everybody is staring at us. She pulls the ice-blue needles from her hair, never taking her eyes off me, and begins to advance.

Last time, I just stood at the back of the class and watched.

I glance over at Mr Flint, wondering what he thinks I’m going to do, but he just returns my gaze and folds his arms, so I guess it’s up to me. Thing is, I don’t have flashing blue hair needles, or fiery eyes – I don’t have anything. I spent most of last night either pacing my room, full of rage at Nan and Peg and the world in general for making things so complicated, or looking at myself, trying to uncover my fae-ness. I said all the familiar spell words with a new zing, wondering if my magic would suddenly burst forth, especially now that my mother’s acorn has merged with my own, but they didn’t act any differently. I don’t even have interesting teeth.

Tash grins. ‘Ready?’

‘Yes,’ I snap, gathering myself and muttering Nan’s words for self-defence. She was always very bossy about self-defence. I just wish she’d taught me a few words of attack as well.

Tash dances forward, clearly determined to find a chink in my armour, but she’s too angry to do it with any subtlety; her eyes flash like mirrors before she strikes with the lightning magic in her needles, and her next move is pretty easy to read. I keep on murmuring the words under my breath, and my clumsy feet don’t let me fall. At one point, there’s even a flash of something that didn’t come from Tash – it’s there and gone again so quickly that I’m not entirely sure what happened, but Tash’s eyes widen in surprise, and after that she’s more cautious.

‘Very good!’ Mr Flint calls out, halting us before I can work out what I did or whether I can do it again.

The acorn at my throat is uncomfortably warm, and I’m fairly sure it did something in there.

‘Let’s change. Excellent defence work, Stella – not at all bad for your first time. Let’s have you out. Tash, you’re getting pretty nifty with those needles – though you need to remember not to rely upon them alone. It is your power that drives them, not the other way around!’

He calls Yanny up to face Tash next, and he’s pretty excellent at the fight. His smoke lingers in the air, and he has a fiery whip that curls around his wrist and snaps in the air. Mr Flint pits student after student against him, but nobody stands for long, until another girl – Laurel – steps in, and they parry with hot words and quick, dancing feet, his whip against the nimble flick of her slim wooden staff, until finally Yanny holds up his hands in defeat – through tiredness if nothing else, by the look of him.

‘You spread yourself too thin, boy!’ Mr Flint snaps from the sidelines. ‘You need to control it better; rage will only carry you so far!’

Yanny nods, tight-lipped, as we’re dismissed.

‘Are you OK?’ I ask him once the lesson is over, while he fixes his glamour out in the corridor. I can feel the stretch of magic in the air, it’s thin, dangerous.

‘Yep,’ he says, rolling his shoulders as we step through the wooden door and head down the stairs.

‘That was intense.’

He shrugs. ‘Yep.’

I don’t know what to say, how to make him feel better. He looks utterly worn out, and there’s a tension around him that makes me anxious. I guess there’s probably nothing I can do right now.

I keep close though, all morning, and Zara senses something too. She doesn’t comment, but I know she’s worried. We get through double English, and then it’s maths, and the winter sun streams through the windows, making patches of searing light across the desks. The radiators are on full blast, and Yanny is struggling, his skin pale beneath bright freckles. I whisper the words of heart, to lend him strength – and for a while, it seems to work. He picks up his pen, fixes his attention on the page before him. But as soon as I’m done with the spell, his hand stills, and he wilts back into the chair.

‘Yanny –’ Zara leans into him – ‘concentrate.’

He sits upright and pulls the book closer.

‘Here,’ she says, shaking her head as she flips the pages. ‘That one. Look, I’ll help you with it later. Just look busy for a minute – Mr Goodenough is on the warpath.’

And he is, his blue eyes flashing around the classroom as if looking for a target. Yanny bends low over his book, as if deep in study, but his eyes are unfocused. Zara frowns over at me.

‘Just say he’s ill or something,’ I whisper.

‘Mr G doesn’t care about that!’

‘Well, he should.’

‘Yanny’s already on a warning. He fell asleep in his lesson last week. Most of the teachers don’t seem to mind, but Mr G does.’

‘He’ll be OK,’ I whisper. ‘There’s only ten minutes left . . .’

I reach deep for new words, thinking of the spell Nan taught me for fortitude. I look down at my own book and mutter the words slowly. They unwind from me, and I can feel the power in them. Yanny stirs next to me, and I keep muttering, until the bell goes, ignoring increasingly quizzical looks from Zara.

‘OK! The next chapter for homework, please,’ says Mr Goodenough. ‘Off you go, slowly. Remember your coats – and I expect better next time!’

He pins me with a stare, and I nod, turning to pack my things, feeling a bit fuzzy-headed.

We scuttle out of the room and head to the cafeteria, but I can’t keep the words going in the rabble of the corridor, and Yanny starts weaving erratically, his eyes flashing.

‘What is your deal?’ Zara demands. ‘Yanny? Stella? What’s going on?’

‘I’ll take him to the, uh, medical room,’ I say.

‘The medical room?’

‘Upstairs.’

She looks between us warily. ‘I’ll help.’

‘No. Leave it with me.’

‘Stella, no. Please don’t do this – don’t exclude me. I know there’s something going on—’

Yanny collides with a glass door and starts to giggle. Out of the corner of my eye, I see Tash charging up the steps, a determined look on her face. If she reports that he’s out of control down here . . .

‘Zara, I’ll explain later, but we have to go. I’m sorry.’

‘Go on, then!’ she bursts, steadying Yanny as he stumbles into us. ‘Go! I’ll wait right here.’

She sits on the bottom of the steps as I hustle Yanny up them and through the charms and the double doors. He’s hot as a small sun, and his shadow boils across the wall as we go. When we reach the time-out room, he staggers and pretty much falls into one of the chairs, and the change is instant.

He is no human.

Fae, through and through, pupils wide and flecked with fire, the outline of his would-be wings clear against the fabric of the chair behind him. His breath steams out as he lets go of the glamour, and his eyes drift closed. I fetch water and perch on the chair next to his, and then Tash strides in with Principal Ashworth.

‘Look!’ she exclaims. ‘Look at the state of him. Wild, he was, downstairs.’

‘He’s fine,’ I say. ‘He’s just tired.’

‘Well he’s here now, and I’ve heard no alarm. We’ll entrust Stella with his care, shall we, Tash?’ Principal Ashworth says, casting a dark look at her.

‘It’s not safe, him being like that around people. He could expose us all.’

‘If you are exposed, young lady, it will be your own doing. Now, I have business to see to, and I suggest that you go and find some lunch.’ Principal Ashworth stares at her until she backs down and flounces out of the room.

He turns his attention to me. ‘Well done for getting him up here. Yanny is rather overtaxed at the moment.’ He looks down at him with a frown. ‘I’m glad he has a friend, Stella. Let me know if there’s anything I can do.’

I nod, and he bustles out again.

I take a deep, steadying breath, thankful there’s nobody else in the room. I don’t know what to do next, and Yanny certainly isn’t going to pass for human any time soon, but at least it’s quiet in here.

Until Zara bounces in.

‘This place is awesome. I snuck in as Tash was leaving. She didn’t even see me, she was in such a strop. What’s going on, Stella? What do you all do up here?’

‘Oh, Zara! You’re not allowed up here – there’s going to be trouble!’

She scowls at me. ‘Well. There’s already trouble, I’d say, and you’d think it would be good to have a friend here to help you. I don’t care what’s happening, so long as you let me help. What is going on with Yanny? I’ve seen him tired before, and he gets clumsy, but that was something else entirely!’

She looks down at him, and her eyes widen.

‘Stella! What . . .’

‘He’s a fairy,’ I say.

‘But –’ She sits hard on the chair next to him. ‘But –’ She stares around the room, her eyes widening at the ethereal glow of the lights in the walls, the silver charms set up high. ‘Oh. But I . . . But –’ She stares at Yanny. ‘What happened to his wings?’

‘It’s part of the shadow curse, I think . . . I don’t know. I’ll explain what I can later, we just need to get him through the afternoon, and then get him home.’

‘How can he go to lessons like this?’

‘I can’t,’ Yanny says with a grin, steam escaping from between his teeth.

Zara flinches, but she sits firm.

‘What happened?’ I ask. ‘Why are you so . . . fae?’

‘The glamouring’s a bit shaky,’ he says, his eyes still closed. ‘I was on watch last night. I thought I could manage. Then Laurel got to me when we were duelling.’

‘Did she hurt you?’

‘No! I’m just tired.’

‘I didn’t think you were allowed to go on watch,’ I say.

‘Watch?’ Zara mouths, but I shake my head.

‘Later, Zara!’

‘Did it anyway,’ he murmurs. ‘And it was fine, the fight was good, but today the . . . the stitches kept coming undone. I couldn’t keep the ends together . . .’

I shake my head. ‘What do you need?’

‘Mrs Mandrake.’

‘Mrs Mandrake? My Mrs Mandrake?’

‘I don’t know whose she is,’ he says, blinking. His pupils have filled his eyes, and Zara swallows hard as she sees it. ‘Pa said . . . I should call her, in an emergency.’ He grabs for his bag, but it falls to the floor, and steam billows from his mouth as he hisses with frustration.

‘Let me,’ Zara says, pushing him back. She reaches down and starts rummaging in the pockets of the bag, eventually finding a crumpled piece of paper with a number on it. She gets out her phone and dials with no hesitation and speaks quick and firm.

‘She’s on her way,’ she says.

‘Oh good,’ says Yanny. ‘That’ll be trouble later.’

‘Never mind later. We need to fix you now,’ she says.

‘OK,’ he whispers, closing his eyes.

Zara gives a low whistle, staring from him to me. ‘I mean, I knew there was stuff going on, and I knew magic was real, but what is all this? It’s a nightmare! How are you involved, Stella? What’s going on?’

‘Let’s just . . . get through this, and I’ll tell you – I promise.’ I hold her gaze and take a deep breath, seeing Nan and Peg in my mind, how horrified they’re going to be, and saying it anyway: ‘You can come to mine after school.’

She nods. ‘OK.’

Mrs Mandrake raises an eyebrow in surprise when she sees us all sitting there. I smile, but it feels a bit hopeless.

‘Stella. Glad to see you’re making friends,’ she says. ‘This must be the Zara your nan spoke about. What a fine mess you’ve got yourself caught up in, my girl. And here is Yanny.’ She frowns, taking in his form. ‘It’s a good job you called.’ She starts rummaging in her bag, eventually coming out with a small purse.

I open my mouth to say something. Anything. But nothing comes out.

‘We’ll talk later,’ she says. ‘Let’s get this boy sorted out for now.’ She stares at him for a moment, noting aloud the steam coming from his nostrils, the monochrome of his complexion.

She looks up at me. ‘His eyes – how do they look?’

‘Um. Fiery. Then his pupils sort of filled them.’

She tuts and unzips a small purse, using tiny silver tweezers to draw out a bunch of very smelly dried twigs.

‘What’s that? Is he going to be OK?’ asks Zara.

‘Oh yes –’ she shakes her head – ‘for now, anyway.’

She looks angry in a way I’ve never seen before. She takes a deep breath and thrusts the bundle under Yanny’s nose. His eyes snap open, and he tries to jerk away, but she holds him firm, her mouth a set line, and slowly whatever she’s doing begins to work. He is still very clearly unhuman, but colour starts to bleed back into his skin.

‘OK,’ she says. ‘That’ll do it.’

‘What was that twig thing?’

‘Bit of a mer-fae nest,’ she says. ‘He’s been overdoing it. Keeping up the glamour is a tall order when you’re half-starved and sleep deprived, never mind all that fighting he’s been doing in there. I’ve just calmed it all down a bit and restored a little of his energy. Now – I’ve got to go. I’ll go and see Principal Ashworth now and make sure you’re not disturbed. I’ll tell him that I’ve allowed you in here, Zara – that should save you all some trouble. We should talk, you and I . . .’ She looks at Zara long and hard, as if making her mind up about something. ‘Yes, we should. Now, get Yanny home once the coast is clear, and make sure he rests. No glamouring for him, not for a good few days.’

And with that, she’s gone, leaving us with a very confused, bleary-eyed Yanny.

‘Well, she’s pretty awesome,’ Zara says. ‘Is she human?’

‘Yes.’

‘So humans can have magic of their own . . .’

‘Course they can,’ whispers Yanny. ‘If they want to.’ He chuckles to himself, steam still billowing.

‘Is this what he usually looks like?’ Zara whispers.

‘Yes, when he’s not using a glamour to disguise himself.’

‘What about you?’ she asks, staring me up and down. ‘Are you like Mrs Mandrake?’

Yanny laughs harder, and the wisps of his wings glow orange. I glower at him.

‘No,’ I say. ‘I’m . . . a bit more like Yanny.’

‘But it doesn’t show?’

‘It’s a long story.’ I try a smile at her, though it feels wobbly – everything feels very precarious right now. Will she mind that I haven’t already told her? ‘Can we talk about it later, once we’re out of here?’

‘Yes,’ she says. ‘And you don’t need to look so panicked about it. I knew there was something different about both of you. Now, how are we going to get him out of here without anyone noticing?’

‘We wait until the last bell goes. And then we’ll just have to go for it.’

‘Stella can glamour for me,’ Yanny says, stumbling to his feet. ‘Come on. I need to get out of here now.’ He looks at Zara. ‘You found your way up, then.’ He gives a broad smile. ‘Knew you would, one day.’

‘You could’ve told me,’ she says.

‘No.’ He shakes his head sadly. ‘Not allowed. Nor was Stella.’

‘It was Tash who let her in,’ I say. ‘But that’s beside the point. Principal Ashworth said there were life-and-death exceptions – and you did look pretty deathly – and Mrs Mandrake said she’d sort it. For now, we need to work out what we’re going to do with you – I can’t glamour!’

‘Oh you can,’ he says tiredly. ‘Just try, please? I need to get home.’

‘I’ve never done it before though – I’ve never needed to!’

‘Lucky you,’ he says. He picks up his bag with a grunt and stands in front of us, pale and swaying on his feet, his expression utterly determined. ‘Come on. Let’s go.’

He tears through the corridor, bangs out through the double doors, and careers down the stairs. Fortunately most of the kids are in lessons, only a couple rushing late, so we charge out with him, through reception, past a startled Mrs Edge, and into the clear, cool air of the mid-afternoon. Yanny sags a little as we reach the school gate, but his pace doesn’t falter, and so we head off towards town.

‘Just cover me,’ he says as we start off down the street. His would-be wings are like dark smoke, the whole sense of him is fierce, fragile, and unmistakeably one hundred per cent fae.

‘I don’t know how to glamour!’ I howl.

‘Wait a minute,’ says Zara, stopping him with her hand. ‘Yanny. Stop.’

‘Zara—’

‘Don’t Zara me. You kept huge secrets, even though I told you all my stuff. I trusted you, Yanny. You were the only person I told about my . . . the separation, when I moved here. And you hid all this! So I am being understanding, I am being a virtual SAINT about it all, but that’s enough. You can’t just command someone else to do something they’re uncomfortable with and expect me to go along with it.’

‘She can do it!’

‘That isn’t the point!’

‘What – she won’t? Fine, then. I’ll just go on my own. Hardly anyone about anyway. Who cares?’

‘I care,’ I say. ‘And I’ll do it, if I can, but I never have before, and I don’t know how, so you’ll have to teach me!’

‘Your words. Your spells. You’ve used them before, in class . . . You use them more than you think. And you tell yourself they’re just words, but they’re not. They’re the language of magic, and they’re powered by the magic in you. That’s what you need to use.’

‘I don’t know the words for glamouring . . .’

‘There aren’t any,’ he says. ‘You just need to feel it. Imagine a barrier between us and the world, see the picture you want everybody else to see, and live in it.’

Zara frowns. ‘What? How’s she supposed to live in it?’

But I get it. I know the feeling he’s talking about. I know about barriers. All the things in our own barrier around our house, they’re just moments of thought, symbols of power. Perhaps I can make my own, without the silver.

‘You’ll have to judge it,’ I say to Zara. ‘Stand clear . . . and let me know if anything changes.’

I stare at Yanny and see him as he is, but also as he makes himself. A little shorter; a little more stout. No wings. Skin and hair, warmer; eyes, less bright; teeth, less sharp. It occurs to me as I’m doing it that I’m diluting the best bits of him, but I push the thought away. It’s distracting.

‘Well?’ I ask Zara, my mind fragmented.

She stares at us.

‘Zara!’

The work I’ve done on Yanny evaporates.

‘Yes!’ she says. ‘Sorry. I was pinching myself. You did it. I mean it was a bit wobbly, and you made him a bit short, but to a casual passer-by . . .’ She shrugs. ‘He’d pass.’

I pull all my thoughts together again, and something Yanny said earlier, about the stitches coming undone, suddenly makes sense. It is like stitching something; a new reality. One piece of deception leads to another, and if you lose yourself halfway, the whole thing sort of collapses. Yanny is uncharacteristically patient while I work; he looks utterly spent.

‘There,’ I whisper. ‘Got it?’

‘You’ve got it,’ Zara says, leaning in and taking hold of Yanny’s hand. ‘Come on. March.’

We wrangle ourselves through the town centre, huddling up tight to each other, avoiding the gaze of anyone we meet. A couple of dogs definitely notice there’s something unusual going on and give us a wide berth, but the people we pass don’t seem to see anything out of place.

We trail around the edge of town, and make our way out on the river path, towards my house and the forest, but as we go, it starts to get harder to see the glamour on him, and he is mostly sleepwalking, leaning into Zara while I focus my energy on seeing him the right way.

‘OK?’ Zara asks after a while, as we head further out of town.

‘Mm,’ I manage. ‘Nearly there . . .’ But as I say it, I realize I can’t get us into the forest past the shadows with him like this, even if his faelight works. My mind is buzzing with the effort of hiding him already. We can’t leave him there to find his way through by himself. There’s only one place we can safely go now.

Home.

I look at Zara. It’s probably time for an explanation.