This fic sets Cackle's Academy and its inhabitants in JKR's wizarding world. I will thus borrow the concepts and the occasional character from the Potterverse, but the story will remain firmly rooted in The Worst Witch world, and will be based primarily at Cackle's itself. I kept seeing references to TWW/HP crossovers, but I've yet to see one of any length that doesn't simply pick up Mildred and Co and dump them in Hogwarts. I don't expect Hogwarts or the Trio to appear in this story at all, except incidentally through hearsay, but I'll probably use my two favourite HP characters: McGonagall and Snape, although I'll try not to overuse them! I'd also like to beg, plead and grovel for a beta. I like this idea, but I need someone to bounce ideas off and keep me focused when the fandom part of my brain goes 'Oh, shiny!' and is tempted to move off to pastures new. At the moment, I envisage this as falling between the 20,000 to 30,000 word mark, but who knows…! Timewise, I'm roughly pegging this as happening in S2 for TWW, and during the year covered by Half Blood Prince for Potterverse. And, of course, all reviews/comments are eagerly devoured!

A PLAGUE ON ALL THEIR HOUSES

Imogen Drill paced the tiny staffroom of Cackle's Academy and shivered. The bitter wind outside blew straight through the glassless windows and flayed her to the bone. Usually the lack of glass was not an issue; usually, the magic of the hundred odd witches who inhabited this old building provided sufficient barrier against the elements. 'Sufficient', not 'comfortable'; Cackle's could never be described as that. For the past weeks, however, that magic had slowly faltered, and the unmagical Imogen presently found herself in the incongruous position of being literally the strongest person in the castle.

She shivered again and pulled her fleece around her, as it tight as it would go. There was no point in suggesting warm-ups, or runs, or a nice spot of gym. Hardly anyone was well enough to benefit, and even those few who were not actively ill were below par, to put it mildly. In short, Cackle's was in the grip of an epidemic that showed no signs of abating any time soon.

Her glum musings were disrupted by a tart interruption.

'Must you wander around in that fashion?' Constance Hardbroom's voice held all of its normal acerbity, but only a fraction of its customary strength, and Imogen turned to look at her.

Cackle's Deputy Headmistress had always been a slender woman, but now she was verging on skeletal. Her eyes burned, the fever-flush made her look almost healthy – but Imogen knew that Miss Hardbroom's usual skintone was pale, and the flush was simply a mockery.

'Do you think Amelia will be able to get help?' Imogen asked, aware that she sounded dangerously close to pleading.

Constance carefully put her pen down – even a fever of over a hundred degrees could not keep her from her marking – and folded her hands tightly on the table. 'I don't know.'

She coughed, harshly, and Imogen restrained herself from rushing over to offer support, knowing that the older woman would only resent it.

'We can't go on like this,' Imogen insisted, putting her hands flat on the time-worn oak table and leaning forward, her elbows straight. 'How long until one – or more – of the girls dies? What will happen to the school then?'

Constance raised one eyebrow. 'Cackle's has survived epidemics before, Miss Drill.' She coughed again, and the hand she raised to her mouth trembled slightly. 'Haven't you noticed? None of us are ill enough to die.'

Imogen snorted. 'Have you looked at yourself lately, Miss Hardbroom? Frankly, I'm surprised you're able to sit up. You should be in bed!'

Constance shook her head in a tiny motion that reflected how little energy she had. 'You don't understand. That's not how this illness works. We're ill because our magical immune systems are in revolt, not our physical bodies. It's our magic that's being burnt away by the fever, and – and the emaciation and other symptoms are merely side effects of that.'

Imogen collapsed limply into one of the chairs – ignoring how it creaked beneath her weight – and stared at her colleague. 'You've lost your magic?' she repeated, stunned.

Who would Constance Hardbroom be without her magic? It permeated her entire being, the roots of her witchily dark hair all the way down to the pointed toes of her equally witchy boots.

For answer, Constance raised her hands in the spell-casting position that Imogen had come to know so well, and pointed them at her. Reflexively, Imogen winced, and she could have sworn that a smirk of a smile tugged at corners of Constance's mouth. It was a wry smirk, she realised at once – for there was no green flash, no spark, no explosion… Cautiously, Imogen reached up to pat herself from head down to waist level, just to check that everything was where and as it should be, and ignored how the smirk almost – almost! – turned into a smile.

'It's nearly gone,' Constance said, once Imogen had finished patting and tugging. 'You're quite safe.' She coughed a third time, doubling up with it, and Imogen stepped forward.

A magic-less Constance Hardbroom seemed suddenly significantly less formidable.

'That's it,' Imogen said loudly, going to the sink and running some water into a chipped glass. 'You're going to bed, Miss Hardbroom, and there's nothing you can do about it.' She grinned as the put the glass in front of the older woman. 'Time to leave the Muggles in charge, my dear.'

When Miss Hardbroom obeyed without a further word, Imogen found herself wishing that she could call that last comment back. She had – she admitted it – been hoping to stir Constance in some kind of retort; that quiet acquiescence was as unexpected as it was terrifying, and the cold coil of fear that Imogen had been trying to ignore for weeks tightened deep within her.

She curled tightly into Miss Cackle's comfy chair next to the fire and prayed for all that she was worth that the Headmistress would come - and come quickly.

It was nearly silent in the dungeons, the quiet broken only by a chorus of harsh breathing and the occasional hacking cough. The members of DOBS had chosen to retreat to their favoured hiding place rather than their dormitories; at least the dungeons were windowless and therefore fractionally warmer than their icy rooms, and here they could be together.

'I'm so sick, sick and sick of being ill,' Enid Nightshade announced petulantly, throwing the book she had been idly thumbing through across the room. Or rather, she tried to throw it, but failed miserably, and the book fell, open, on the floor.

'If I didn't feel like dying, Enid Nightshade, I'd think about setting HB on you for that,' came a weak voice from the other side of the dungeons. When DOBS had announced their intentions for the duration, Fenella Feverfew and Griselda Blackwood had immediately declared themselves to be honorary members, and joined them forthwith. 'That's the only copy of Magical Maladies our library has, and it's nearly three hundred years old.'

'It's okay, Fenny. She hasn't hurt it,' Griselda assured her, having crawled across the room to check. 'It's a little crumpled but we can soon fix that.'

'Can we?' Jadu Wali asked, a cough hitched fore and aft.

Enid groaned. 'Don't be cryptic, Jadu, please. What do you mean by that?'

'She only means we can't fix it – normally. Magically, I mean,' Mildred Hubble supplied, looking ruefully down at her long slim fingers. 'Look!' She pointed her fingers at the hapless book and muttered something, and her friends reared back, experience having taught them long ago that Mildred's magical actions rarely matched her impeccable intentions.

In this case, their caution was unnecessary. Nothing happened, and Mildred sighed and huddled up against the cushions of the beaten old sofa . 'See?' she said sadly. 'It's all gone. Funny how you miss it, even when you're as rubbish at it as I am.'

'Do you think we'll ever get it back?' Maud Moonshine asked, wiggling her own fingers. She shivered. 'Even though this place has never been exactly comfortable, I've always felt … safe, here. If we've lost all our magic, it's just become another draughty old castle.'

'It almost makes you wish we'd let Mr Hallow get ahead with his plans to give us a swanky new place, doesn't it?' Ruby Cherrytree put in. 'It would've had have central heating, Miss Drill said. Muggle central heating, the kind you can switch on and off.' Her tone was longing. Like Mildred and Jadu, her parents were Muggles and she was missing the comforts of home rather desperately just now.

'I don't think HB'd like that,' Mildred said. Then an idea occurred to her, and she sat bolt upright, moaning quietly when the movement send a shot of red-hot pain through her head. 'There's a thought. What if HB's lost all her magic too?'

The others looked grave. None of them would claim to be especially fond of Cackle's relentlessly strict Deputy Headmistress, but they all respected her magical strength, even when they grumbled about her disciplinary edicts.

'That must be why Miss Cackle has gone to the MM,' Fenella said. 'No-one would worry if it was just us. They'd just say something about our ages and how of course we must expect fluctuations in our magic, until –er – everything settles down.' She grinned, the sight a hideous one in the candlelight. 'D'you think any of our esteemed mistresses have ever heard of hormones?'

'Why the Ministry, though?' Griselda queried. 'Why not the Council? Won't the Ministry send her away with a flea in her ear?'

'Miss Cackle mustn't be too badly off,' Ruby added. 'If that was an option, HB'd have gone. Can you imagine anyone sending her off with a flea anywhere?'

Despite their poor health, the girls grinned, but their grins died at once.

'Miss Cackle and HB must think this is all too serious for the Council,' Maud said with her usual good sense. 'That's why she's gone to the Ministry. To – to report it, and ask for help.' She pulled her blanket closer. 'There's darkness coming, can't you feel it? Something is wrong with our world.'

Amelia Cackle exited the Minister's office, a dumpy little figure in worn black. Her shoulders were slumped, for her visit had been spectacularly useless. The Minister had made it all too clear that he believed she was making an enormous fuss about nothing. He'd hemmed and hawed about how it was time Cackle's Academy started taking notice of what was going on in the wizarding world, instead of being so insular. The last word had almost been growled – the Minister, Amelia felt, was positively leonine – and she was then dismissed by the simple and impolite means of magically propelling her out the door.

She stood in the atrium of the Ministry, taking it in. Its grandeur alienated her, a testimony to the hubris of various past Ministers. The smooth surfaces and large statues were totally foreign to her; she was accustomed to buildings that wore their age proudly, if shabbily. And the people. Despite the Minister's rantings, the atrium was busy, and Amelia blinked, intimidated by the thought that all of these men and women were magical, and almost definitely more powerful than she was. Her shoulders drooped further, and she wished yet again that Constance had been able to make this trip.

The wish turned into an imagined encounter almost at once, and Amelia straightened, her chin coming up. She might not be anything to speak of, magically, but she would back her deputy against any one of these puffed up witches and wizards, with their fine robes and fancy Hogwarts educations.

That is, I'd back her when she's well, she mentally edited, and despair overwhelmed her, causing her to drop rather limply onto the rim of the nearby fountain.

We're finished, she admitted to herself. A thousand years of witch education gone, just like that, and all because of some virus. What would Great-Great… however many greats it is … Granny Cackle say?

She was just trying to think of how she could break the news gently when a shadow fell across her, and she glanced up, half expecting it to be another self-important Ministry official who would ignore her.

Instead, the figure before her was oddly familiar. Tall, thin, garbed in black, black hair twisted in a tight bun…

'Amelia Cackle, isn't it?' the figure asked, and Amelia's despair slid away like a dropped cloak.

She bounded to her feet, and grabbed the tall woman's arm with both her hands. 'Professor McGonagall!' she exclaimed, exuberant in her relief at seeing a familiar face. 'You have no idea of how happy I am to see you! Absolutely delighted!'

Minerva McGonagall was clearly startled by this enthusiastic greeting. 'I see,' she said, gently detaching herself. Then her eyes narrowed behind her glasses, and her lips thinned. 'Is everything quite all right, Miss Cackle? I don't believe we've ever met in these surroundings before.'

Amelia beamed. 'No, the last time we met was when Constance was promoted to Deputy Headmistress, wasn't it? And that was at Cackle's. You had a tour,' she ended, rather lamely, remembering McGonagall's stunned silence in response to Castle Overblow's shabbier bits.

'It was a very enjoyable day,' Professor McGonagall responded diplomatically, but Amelia was only too aware that her sharp gaze was roving up and down, no doubt noticing the thin patches in Amelia's robe, and the fact that she had clearly lost weight.

'Have you been unwell?' McGonagall demanded, her bluntness reminding Amelia inescapably of her cousin, Constance.

'Only a little.' It was a feeble response, Amelia knew, but it was the truth. She had come through the epidemic relatively unscathed, thus far. Anxiously, she peered up at McGonagall, examining the other woman through her horn rimmed glasses. Would Minerva McGonagall be willing to help?

She drew herself up. It was important that McGonagall take her seriously, and not simply consider her as the slightly bonkers principal of Cackle's (although she was fairly certain that would not in itself deter the older woman; after working with Dumbledore, McGonagall must surely be accustomed to eccentric Heads). 'Professor McGonagall –'

'Minerva,' that lady stated firmly. 'We are colleagues, after all.'

Amelia nodded her thanks. 'Minerva, then. I – oh, it's all so puzzling. Everything is not well at Cackle's, or with Constance.' Amelia's eyes dropped to the shiny black floor, vaguely aware of the reflections that danced and skittered on the smooth surface. '

'Go on,' Minerva urged, almost as if Amelia was a student.

'Three weeks ago, one of the second years, Mildred Hubble, came down with a – a – well, we thought it was a cold. Mildred's never been very good at shielding charms,' she explained quickly, 'and I suppose it was rather nippy.'

McGonagall raised an eyebrow in a fashion that reminded Amelia, again, of Constance.

'We packed her off to bed in the sick room in the dungeons, because there's no draughts down there, and Constance dosed her up to the eyes. But nothing worked. Her temperature just went up and up … and then her magic went. She did recover, a bit, but not enough. Even now, she's not the girl she was, and … well, it's Mildred Hubble, and she's almost a wraith.'

'I believe I recollect that name from Constance's letters,' Minerva put in thoughtfully. 'Isn't she the girl Constance calls the "worst witch in the school"?'

Despite everything, Amelia laughed. 'She is. Constance and Mildred have an – uh – clash of personalities.'

'I see. That's not all though, is it?'

Amelia shook her head. 'If only. No, Mildred was only the first. One by one all of the girls and staff succumbed. Only the Muggles – Miss Drill, Frank, and Mrs Tapioca – have been immune.'

'And you,' Minerva observed thoughtfully.

Amelia could feel the tide of colour wash across her face. 'Not entirely,' she returned with dignity. 'I am a witch, I'm just … not a very powerful one,' she went on in a rush, acutely aware that she was speaking to one of the most powerful (in more way that one) witches in their world. 'The severity of the illness seems to correlate to one's power.'

'So Constance has been severely affected,' Minerva said softly, and Amelia nodded.

'Exactly. Without Constance we're vulnerable, Professor. Even the castle has become increasingly unliveable; we hadn't realised how much the residual magic was keeping the place going.'

'A cherry ripe for the plucking,' Minerva mused. Her brows contracted. 'This is not good, Amelia. Leave it with me. I'm going back to Hogwarts now and I'll have a word with Poppy Pomfrey and Severus. We may be able to help. In the meantime, we may need to send people up to scout; I don't like to think of all of you up there, ill and helpless, with Voldemort on the rampage.'

Amelia blinked. 'Voldy-what?'

Minerva sighed. 'Don't any of you people ever read the news?' With a practiced flip of her wand, she conjured a newspaper and handed it to Amelia. 'Here. Read it. Show it to Constance. And, for Merlin's sake, be careful!'

And with that, she was gone, leaving an openmouthed Amelia behind her. 'I wish they wouldn't do that,' she muttered, a trifle peevishly, as she shook the paper open.

AZKABAN BREACHED! DEATHEATERS ESCAPE! the headline screamed. Under it was a series of moving portraits, and Amelia's breath caught in her throat as she saw one she recognised.

In between a picture of a snarling brunette labelled as 'Bellatrix Black' and another smaller figure ('Alecto Carrow') there was a face that was literally as familiar to Amelia as her own.

Her twin sister and nemesis, Agatha Cackle.

So, what's the verdict? Worth continuing? Reviews = confidence boost = motivation = more fic! *shameless begging*