© 2012 Mundungus42 All rights reserved. This work may not be archived, reproduced, or distributed in any format without prior written permission from the author. This is an amateur non-profit work, and is not intended to infringe on copyrights held by JK Rowling or any other lawful holder. Permission may be obtained by e-mailing the author at mundungus42 at yahoo dot com

~o0o~

When the last of the dummy Inferi lies in a smouldering heap on the floor, Professor Snape dismisses the Defence class with only a modicum of threatening. Ron and Harry make a beeline for the door, but Hermione lingers. Professor Snape is obviously aware of her presence, but he makes a show of marking essays. She stands at a respectful distance and waits.

Finally he sighs loudly and lays his quill aside. 'What do you want, Granger?'

'I just wanted to apologise—'

'I'm sure you do. Can you think of any reason that I should allow you the privilege of doing so?'

She isn't certain how to respond to this. 'You should hear me out because it's the only way you'll know exactly what I did.'

Her last words lilt up interrogatively, and the effect on him is electric. He slams his palm on the desk with enough force to dislodge two homework scrolls from the pile and send them tumbling to the floor.

'You seem to be under the mistaken impression that you know something I do not. I assure you, Miss Granger, not only do I know every one of your actions that occurred in my vicinity two nights ago, but I would be willing to wager that I know what you did afterwards. The Headmaster may have blocked my attempts to punish you for your flagrant disregard for safety, but if he were to know of your felonious proclivities, you would certainly be expelled. I refuse to grant you any more unearned privileges. You will have neither the opportunity to apologise nor to atone. Should you attempt to speak to me again about anything unrelated to the subject I currently teach, I will assign you detention with Mr Filch. Now remove yourself from my presence before I lose my temper.'

Hermione's heart is beating a tattoo against her ribcage. 'If you tell the Headmaster, you'll have to tell him which book it was.'

He sits back in his chair, rather like a cobra coiling to strike. 'I hope I misunderstand your purpose in asking that question. Because if I do not, attempted blackmail is an even more serious offence than stealing and reading an age-restricted book.'

'I just thought you wouldn't want the Headmaster to know—' she can't say it.

He crosses his arms.

'That you're—' The words catch in her throat again. 'That the book holds appeal for you.'

He looks at her for a long moment and raises his chin. Though he's sitting, she feels as though he's towering over her. She wants to look away, but his dark eyes are glittering dangerously. 'Considering your increasingly reckless attempts to lay hands on the book, I should think that your own interest in it would be of greater interest to the Headmaster. Or perhaps your little boyfriend?'

Hermione's cheeks flush scarlet.

'I confess myself surprised at you, Miss Granger, for all that I shouldn't be,' he continues, his voice like frozen velvet. 'I knew the company you kept was unfortunate, but I hadn't grasped the thoroughness with which you've been indoctrinated into their hypocrisy.'

Her thoughts are a jumble. She opens her mouth to protest, but there are no words. Her silence seems to inflame him further. He leaps to his feet, rocketing his chair back into the chalk rail of the blackboard. His eyes feel as though they're boring into hers.

'You dare to judge me for reading a book that you yourself have begun reading and ardently desire to finish? Are you so lacking in perspicacity that you cannot think of a dozen legitimate reasons that I might be reading it? Did you truly think to shame me for reading something that I am perfectly within my rights to read? For all your vaunted intellect, can you be that mind-numbingly stupid?'

Fire dances in his eyes as he continues to verbally flay her, and he leans forward, gripping the edge of his desk. She takes a step backwards, helpless in his onslaught. He is towering over her now, and she can't look away from his eyes. She realises that he has stopped speaking and is looking down at her with a look of surprise that fades into a sneer almost immediately.

'I believe you're not here to apologise at all, Miss Granger. I think you're here for another reason entirely.'

Until this moment, Hermione believed she truly wanted to apologise for harming him, but his words hit their mark, and her knees threaten to buckle as she grasps the effect that his voice and his fury are having on her. Her heart is hammering in her throat in elation that he's divined the truth and absolute panic.

She takes a bold step forward so that her hips brush the front of his desk. 'Yes.'

The word, spoken calmly and clearly, breaks the spell, and he sits down once more and takes up his grading quill. 'Detention. If you must indulge in schoolgirl fantasies, I suggest you keep them to yourself, as they are as unwelcome as they are a waste of my time. Remove yourself from my classroom immediately.'

Hermione blinks in surprise, wondering if she imagined that the fire in his eyes was there in the first place. Wordlessly, she gathers her things, but pauses in the doorway.

'Professor Snape?'

'Two nights of detention.'

'May I borrow the book when you're finished with it?'

She swears his lips twitch. 'A week of detention. And no.'

She nods and leaves the room. In the hallway, she lets out a shuddering sigh.

~o0o~

To Hermione's immense satisfaction, Lucius Malfoy nearly sprays champagne out his nose. d'Aubigny, or rather, Severus Snape, merely looks at her curiously.

'An interesting toast, cherie,' he says, still doing his uncanny impression of David Suchet's Hercule Poirot. 'One wonders what you mean by it.'

'It means the jig is up,' says Hermione, sipping her drink. Unsurprisingly, it's delicious. 'Laurence d'Aubigny, while charming and brilliant, is as real as the Easter Bunny.'

A look passes between the two men, and d'Aubigny capitulates with a shrug. 'It is not entirely fair to say so, ma petite,' he says, sounding only slightly less French. 'The Easter Bunny hasn't published in any of the top journals.'

Hermione grins. 'Touché.' She practically vibrates with pleasure as she gathers her notes and gestures for them both to sit. 'I've found a number of potions recipes in the Marquis's journals, though it's obvious that he had far greater ambition than skill. Almost all of them contain base potions purchased at the local apothecary.'

Lucius looks momentarily lost before he grasps the abrupt leap of subject and realises that Hermione isn't going to gloat over her discovery. Severus, who has peeled off d'Aubigny's whiskers and rolled them into a piece of velvet for storage, nods.

'There are several references in the text to bought potions,' he says. 'Fortunately for us, the French levied draconian punishments on those who tried to sell fraudulent or dangerous potions. The third edition of Antoine Parapluie's codex was published a few years before the Marquis was imprisoned and the fourth wasn't finished until after his death, so any potion mentioned in any of our sources is likely to have been created using third edition protocols.'

As he speaks, he scrubs his brows with his handkerchief, turning them progressively darker. Hermione is fascinated by the transformation, which is completed when he lifts the shock of white hair from his head, releasing a spill of silvering black hair across his forehead. The informal, almost romantic style flatters his face in a way that the greasy curtain she recalls never did. The difference between d'Aubigny and this younger man are notable, but the difference between him and the Severus Snape she knew all those years ago could not be more striking.

Lucius is thumbing through Hermione's notes. 'What about this one?' he asks, sliding the parchment across the table so they can both read it. 'It calls for an expired restorative draught, which likely contains mandrake, as well as unicorn blood. The blood alone could account for the broken magic.'

Hermione smiles at Lucius's description of the magic as 'broken.' It's a good way of putting it. 'I don't think so. Unicorn blood is a dark ingredient, but it's more likely to taint power than break it. I don't know that we're looking for anything beyond the spoiled mandrake unless it's some sort of transformative element — something like dragonwort that reacts strongly with mandrake to the point that it interferes with magic's ability to hold itself together.'

'A sort of magical venom,' muses Severus. 'Though I doubt it will be as simple as identifying one. The venom of all known magical creatures has been well-characterised in almost every conceivable dosage.'

'Then perhaps an interference of some sort,' says Hermione. 'The Merlin particles could be a combination of the broken magic and the breaking agent.'

'What about a combination of magical techniques?' asks Lucius, who opens one of the journals.

'Like a hex?' asks Severus.

'Or a repurposed Charm.' He holds out a page containing a recipe that Hermione has faithfully copied out. 'Look at the line preceding.'

'Brewing this potion calls for the utmost silence.'

Severus looks thoughtful. 'It also contains a spoilt potion in which mandrake is the active ingredient.'

Hermione stares at the page, trying to imagine what effect a Silencing Charm would have. 'Unbelievable,' she murmurs. She looks at Lucius and Severus in turn, 'Muggles have developed a chemical method of silencing specific sections of genetic material to see what molecular pathways are interrupted. What if de Sade found a Charmed potion to reversibly silence a person's magic?'

'There is no way to know that this potion is what causes the effects described in the text,' said Severus.

Lucius settles back in his chair and sips his champagne. 'There is one way.'

Hermione meets Lucius's eyes to see if he means what she thinks he means. There is clearly an invitation there, and no small amount of mischief.

'No.'

Hermione is surprised that Severus's voice is so flat. 'Why not?'

'This potion contains ingredients that could permanently inhibit a person's ability to do magic. It would be foolhardy to consider reconstruction from these sources outside a facility with any less then level four magical containment in place.'

'Working for the French Ministry has dulled your sense of adventure, old man,' says Lucius. 'You can't even use mandrake there without filling out three forms and using a union technician to prepare and add it.'

'We also have a number of ways to test a potion that don't involve drinking it ourselves,' says Severus, crossing his arms.

'We needn't test it on ourselves,' says Hermione. 'But we can see if the colour matches Martaine's description in the book.'

'Not to support Severus's argument any more than necessary,' said Lucius 'but the journal containing this recipe dates from 1794, and 120 Dayswas written decades prior to that. It's altogether possible that the potion as described in the book was a figment of de Sade's imagination. You may recall there were a number of encounters that are impossible, even with magic.'

Hermione recalls several scientifically dubious anecdotes and shudders.

'So where does that leave us?' asks Severus, crossing his arms.

'I think we should leave it up to Hermione,' says Lucius. 'We did promise to be at her disposal.'

Severus looks at her and clearly doesn't like what he sees on her face. 'You cannot be entertaining what Lucius suggests. It would be dangerous and unethical.'

Hermione schools her features to calm. 'Have you ever worked with rotten mandrake root before?'

'Yes. It's volatile and emits toxic fumes if brewed improperly.'

'I haven't. Thus, it would be safer for me to brew with you present. Given that our work here is sanctioned by the owner and rights holder of the primary texts, provided we follow the rules of collaboration as set out between our two institutions, I don't see how this could be considered unethical.'

Lucius's smirk widens. 'My thoughts precisely.'

'You are on holiday,' says Severus. 'Surely there's something else you'd rather be doing.'

Hermione suppresses a grin seeing the put-upon expression she remembers fondly. It wouldn't do to gloat. 'I can't think of anywhere else I'd rather be.'

~o0o~

After serving a mind-numbing week of detentions with Mr Filch, Hermione returns to the library to research what, if not lycanthropy, is ailing Professor Snape. Her first attempt to ask Madam Pomfrey resulted in being shooed from the hospital wing with a lecture on patient confidentiality still ringing in her ears.

The next line of inquiry is the Encyclopaedia of Potions, which comprises forty enormous volumes with tiny print and is an exhaustive resource for potions ingredients, their preparations, primary and secondary uses, and instructions for handling them. Her search reveals no commonly cited health problems associated with handling any of the Wolfsbane ingredients except for the Quintaped liver, which, in the words of one expert, should not be handled by anyone, ever.

Next, she turns to what magical medical resources she can find in the library, though apart from medicinal potions books, there aren't many. Mediwizardry, she finds, is largely learned through a rigid apprenticeship system, and its secrets are closely guarded. It's only in desperation that Hermione writes an only slightly disingenuous letter to Healer Claypool, a senior researcher at St Mungo's, explaining that she is considering a career in healing and requesting recommendations for introductory texts on the subject.

To her shock and delight, a flock of owls appears the next day with a warm letter from Healer Claypool and a stack of books so massive that she has to recruit Ron to help her carry them back to Gryffindor tower. She feels Professor Snape's glare between her shoulder blades, but she ignores it. Ron is dead chuffed to be asked for help, which momentarily distracts him from moaning over the upcoming Quidditch match against Slytherin.

That night, she begins to understand how complex healing is, but also how antiquated. Before long, the first pages of Healer Claypool's An Introduction to Magical Ailments and Complaints resemble the Half-Blood Prince's copy of Advanced Potion-Making as Hermione, the daughter of health professionals, begins to ask questions.

~o0o~

Lucius Malfoy's laboratory looks like it hasn't seen much use in recent centuries, but it's laid out sensibly with a desk for Lucius and all his books by the window, and the bench is large enough to accommodate her and Severus, should they actually attempt brewing. For all of his grousing, he's clearly excited, and neither of them is immune to the history of the place. Still, it's a relief to see some sign of the man she knew, though she is certain that pretending to be d'Aubigny for so many years has softened his edges as much as being the black bat of the dungeons sharpened them. For all that she's thrilled beyond words that she has the opportunity to work shoulder-to-shoulder with him, she's glad that the proud, cranky man that she admired and feared is still reasonably intact after everything he's been through.

As they bicker over the proportion of mandrake to newt knuckles, Lucius occasionally reads aloud sections from the texts that, to her surprise, show some insight into de Sade's knowledge and style of doing magic. She supposes she shouldn't be surprised that Lucius has read every scrap of de Sade's writing, though not for the reason she might have ascribed twenty-four hours before.

He is the de facto curator of a historically significant collection of the Marquis's books and papers, and it may well prove to be scientifically important, too. It's no wonder that he, whose unfortunate political choices have made him nearly as infamous in his home country as his best-known ancestor was in his, should seek to rehabilitate the image of that ancestor. If even the Marquis de Sade wasn't all bad, surely there's hope for Lucius Malfoy. There's certainly a healthy bit of vanity in his actions, of course, but it's also clear that he takes his responsibility very seriously. More seriously than his interest in her, anyway, which has become less flirtatious and more matter-of-fact, to Hermione's relief.

She catches him looking at her as Severus is converting livresto kilograms, and the blood rushes to her cheeks as she realises how she must look to him, looking over Severus's shoulder as he works, eager as she'd been eighteen years ago. And yet, she knows as she returns his smile that her discomfiture is unnecessary.

After a few hours of largely theoretical work and creating lists of known and suspected ingredients, Lucius announces that it's time for supper. Hermione is surprised to realise that she's famished.

'Fascinating how hungry doing nothing can make one,' Severus grumbles. But his hand is warm in hers as they follow Lucius down the corridor.

~o0o~

The Slug Club party in Slughorn's chambers is shaping up to be an unmitigated disaster.

She tries not to think about Ron, but the great pillock's absence is nearly as irritating as his presence. She has tried to make the best of it with McClaggen, but she very quickly realises that as pleasurable as reading about such things can be, she is not at all interested in a bloke who doesn't understand the word 'no.' Fortunately, her D.A. training ensures that she is far quicker on the draw than he is. The vacant look on his face as she hits him with a Confundus Charm is the highlight of the evening thus far.

When she emerges from the curtained alcove, she straightens her robes and spots Harry and Luna and joins them for a few minutes before, to Hermione's dismay, Cormac emerges, shaking his head as if to clear water from his ears. She stops talking midsentence and ducks behind the group of pipe-smoking warlocks. Cormac must have troll blood in him, to have recovered so quickly.

She is soon engaged in talk by a scruffy wizard named Herman who, she quickly gleans, is a member of the Weird Sisters. To Hermione's surprise, he's quite nice and delighted to find that she knows enough about music to discuss nonstandard lute tuning. Hermione is about to recommend the consort she grew up listening to when there's a loud choking sound from behind them. She spots Harry, his face dribbling mead but grinning, standing with Luna and Professors Slughorn and Snape, and beyond that, Filch dragging Malfoy into the party.

Herman looks bewildered, and Hermione explains Draco and Harry's rivalry, which, to Hermione's chagrin, gets Herman talking about Quidditch. She excuses herself to the drinks table, taking care to ensure that Cormac is staring interestedly at an ornamental column before moving out into the open. She seizes a goblet of mead and retreats to a dark shadow where she finds herself next to a tall, slender gentleman in black who seems equally disinclined to speak as he nibbles halfheartedly on a pasty.

From this vantage point, she sees Professor Snape escorting Draco out of the room and Harry close on his heels, putting his hand into his pocket, where Hermione suspects his Invisibility Cloak resides. She sighs. There's no talking to Harry when he's convinced of something. She smiles as she reflects that the same could be said of her.

'What a miserable night,' says the man, tossing the unfinished pasty on a passing h'ors d'oeuvre tray.

'I'll drink to that,' she says raising her glass.

"I don't drink... mead," he says with a sniff. "But I suppose you know that already.'

Hermione takes another look at him. Is he one of the Weird Sisters? No, they're all over with Slughorn. She takes one look at his pale face and the dark circles under his colourless eyes, but his features register as a blank in her memory. She is confident she's never seen him before. 'I'm afraid I don't know who you are, sir.'

He looks at her disbelievingly, but after a moment he laughs and offers her his hand. 'My given name is Lorenzo Boccarosso.'

'I'm Hermione Granger,' she says, shaking his hand. 'Why do you say your 'given name?''

'An astute question,' he says, clearly pleased to have been asked. 'I am also known as Sanguini, leader of the Famiglia Boccarosso.'

Of course — the inability to eat or drink human fare indicate that he's vampire, and she recalls from a long-ago Defence lesson that their clan lords tend to be the oldest and most powerful. A thousand impertinent questions spring to mind about the commonly-held beliefs about vampire culture, habits, and diet, but she notes the dark circles under his eyes again. He's hiding from the rest of the party, too. After a moment's deliberation, she decides not to interrogate him unless he's in the mood to be bothered.

'Should I call you Signor Boccarosso or Sanguini?' she asks lightly.

He smiles, revealing pointed canines that would be rather frightening if not for the warmth in his eyes. 'Lorenzo, if you please. Now, if you will forgive the liberty, I sense that you have received unwanted attentions.'

Hermione blinks. 'How did you know?'

'First of all, you are hiding in a dark corner with a vampire at a party. Your hair has been mussed and your robe is slightly torn at the neck,' he says, giving an apologetic smile. 'I couldn't help but notice.'

'The situation has been dealt with,' says Hermione tightly.

Lorenzo surveys the crowd. 'The young hulk who seems so fascinated by the surface of the punch bowl. Your work?'

'Yes. I think he's building up an immunity to Confundus Charms.'

'Such a man deserves more than a Confundus Charm.'

'It's not entirely his fault. I did invite him.'

'Did you invite him to take such liberties?' asks Lorenzo, his pale eyes flashing red.

'He seemed to think it was part of the invitation.'

Lorenzo waves his hand dismissively. 'I do not understand where a man would get such an idea.'

'I don't know how much you know about the politics here, sir, but there is a movement afoot that seeks to impose a strict social hierarchy, and people from nonmagical families, like me, are very close to the bottom of it. Cormac comes from an old wizarding family and perhaps feels that he's due the deference of those lower on the social ladder.'

'You agree with this?'

'Of course not! It's what I and my friends are fighting against.'

'Good. Because where I come from, power is power, regardless of one's parentage. You, little one, crackle with it. I hope for your cause's sake that mercy stayed your hand rather than the feeling that you haven't the right to wield your full strength.''

Hermione is at a loss for words. Fortunately, he does not seem to require a response. A house-elf with a tray wanders by, and Hermione catches a whiff of the spicy prawns on skewers. Lorenzo covers his mouth and nose with a handkerchief. Of course — the garlic.

'Is this England or is it France?'

'Professor Slughorn is something of a gourmand,' says Hermione apologetically.

'There appears to be little that he doesn't eat.'

Hermione laughs, and the sound falls into a lull in the room's conversation. To her dismay, Professor Slughorn turns and sees them.

'That's where you've got to, Sanguini!' he says jovially. He wraps an arm around each of them and ushers them to the centre of the room, where a group of old men is gathered. 'I see you've met Hermione Granger. One of my top students, had the book practically memorised on the first day! And a close friend of Harry Potter's,' he says, giving one of the gathered wizards a knowing wink.

'Hermione was kind enough to explain to me some of England's cultural traditions and the current political climate,' says Lorenzo, giving her a wry smile.

The smile on Slughorn's face falls slightly. 'Not a terribly festive subject. But won't you have some of the blood sausage, Sanguini? I ordered it especially for you.'

'Thank you, but no. I have little appetite. I encountered some garlic earlier, and I'm afraid I've not yet 'built up an immunity' to it, as Hermione would say.'

'What a charming turn of phrase,' says one of the older wizards. 'I've never heard it before. Is it one of your new-fangled expressions?'

Hermione feels her face flush. 'It's a Muggle phrase, sir, referring to the immune system's response to repeated exposure to a pathogen. Immunity is conferred when the body can produce enough antibodies to destroy the pathogen before it makes one sick.'

'An answer taken verbatim from a book, no doubt.'

Hermione turns and finds Professor Snape looking down his nose at her. She smiles and succumbs to the reckless urge to answer saucily. 'But correct in essentials, sir?'

He scowls at her, and Slughorn roars with laughter. 'You're going to have to work harder than that to intimidate this one, Severus.'

'I imagine very little intimidates Miss Granger, unless it's the loss of a large number of house points or the threat of a poor mark.'

'Pax, Severus!' exclaims Slughorn. 'It is Christmas! I won't have you deducting points!'

'To blazes with Christmas,' says one of the smallest wizards, who brandishes a large ear trumpet. 'I want to hear more about immunity. Why don't Muggles simply take Pepper-Up?'

'Pepper-Up Potion merely treats the symptoms, not the infection,' says Professor Snape, giving Hermione a quelling look.

She ignores him. 'Muggle science is trying to work out why we become sick and to prevent it. For example, one method they use to prevent disease is vaccination, where partial or heat-killed germs are introduced to the body to provoke the immune response without sickening the patient. That way, if the person ever encounters the germ, the immune system kills the germs before they can make the person sick.'

Even Slughorn appears slightly interested. 'One of my old students, Vanessa Claypool, is a researcher at St Mungo's, you know.''

'Oh yes! I wrote to her about potentially pursuing a career in healing, and she was kind enough to send me some books to read.'

Professor Snape makes a scoffing noise, which both of them ignore. 'I would be delighted to write you a letter of recommendation,' says Slughorn, radiating avuncular pride for a moment before making a beeline for a drinks tray passing his vicinity.

Hermione is disappointed to see that one of the men has commandeered Sanguini and steered him off towards several tall, athletic-looking witches, and she finds herself left alone with Professor Snape. Now that he's standing quite close to her, she sees that he has circles under his eyes to rival the vampire's. Could he be— ? Definitely not. She's seen him in sunlight at Quidditch matches.

'Healing is clearly not your field, Miss Granger.'

Rather than explicitly defy his order not to speak to him on subjects not pertaining to Defence, she merely cocks an interrogative eyebrow at him.

'Watching you show off for Horace's cronies was enough to make anybody sick.'

On any other night in any other circumstances, Hermione would have been mortified. But tonight, after successfully fighting off McClaggen, befriending a vampire lord, and not making an arse of herself in front of Professor Slughorn's friends, she feels more confident than she has in weeks. She feels powerful tonight — apparently she crackles with it.

'And I didn't even need to expose you to aconite fumes this time,' she says.

She can't tell if it's humour or anger that makes his lips twitch. 'Detention.'

And suddenly, his knowledge of the immune system and his symptoms crash together in her brain, and she fairly vibrates with excitement at the only explanation that makes sense of it all. 'When did you develop the allergy, sir?'

'Lower your voice, foolish girl! Two nights of detention!'

He hasn't denied it! Adrenaline floods her veins. 'Is it only the aconite? Or is it other things, too? The silver? Hawthorn?'

'Silence,' he hisses, seizing her glass of mead. 'You've clearly had enough, Miss Granger. I will see you back to your common room before you get into any further mischief.'

He all but drags her from Professor Slughorn's quarters, and as they're rounding the stairs, Cormac staggers out from behind a suit of armour.

'There you are,' he says to Hermione, seizing her other arm roughly, completely oblivious to Professor Snape's presence. 'I've been looking all over for you. We're not finished.'

'I beg to differ, McClaggen.' The wand is in his hand in the blink of an eye. 'Obliviate!'

McClaggen sags to the floor, catatonic. Professor Snape gives her a poisonous smile. 'I trust you'll be more emphatic in discouraging him in the future.'

'Y-yes, sir.'

He whisks off down the corridor, and she follows dutifully.

When they reach the Fat Lady's portrait, he gives the password, and the portrait swings open.

'Thank you for dealing with McClaggen, sir. He won't catch me at a disadvantage again.'

'I trust that he won't. And Miss Granger?'

She pauses in the doorway.

'Should you desire a letter of recommendation to Healer Claypool, I am far better qualified to write a letter of recommendation than Horace, having endured many more years of your intellectual curiosity.'

'Thank you, I— that is, thank you,' she says lamely.

'Don't thank me until you've met Healer Claypool. You are of such similar temperament that you will either be friends within minutes or mortal enemies.'

She has no desire to stop the smile that spreads across her face. 'I'll bear that in mind. Thank you, sir.'

He makes a dismissive noise, but Hermione catches a ghost of a smile on his lips as he stalks off down the corridor.

~o0o~

After a five-course meal and some outrageous anecdotes from Lucius, the three of them retire to the laboratory, and Hermione accepts a glass of Port that she swears is refilling itself.

Severus and Lucius are arguing over a fine detail of translation, and Hermione decides that if she doesn't do something, she is going to fall asleep. She rises from the bench and begins taking stock of the ingredients, most of which appear to be quite old.

The men look up from their parchment.

'Are you planning to brew tonight?' asks Lucius.

'I'm checking your stocks for expired ingredients,' she says, pulling the stopper out of a bottle of frogwort and sniffing experimentally. It's not only gone off, it's gone rancid. She replaces the stopper with a grimace. 'We can send an elf to the apothecary to restock if needed.'

To her surprise, both men cast Bubble-Head Charms. 'Are you allergic, too?' she asks Lucius.

It's a simple enough question, or so she thinks. However, the expressions of bonhomie are immediately wiped from her companions' faces. 'Too?' asks Lucius, looking at Severus.

'Answer the healer's question, Lucius.'

'I hardly think it's relevant.'

'It may well be,' says Hermione, leaving the bottles on the workbench. 'In epidemiology, they use the word 'cluster' to describe a group of unrelated people who develop similar medical conditions. The larger the sample size, the more likely it is that we can isolate what it is that's made them ill.'

'A sample size of two is hardly a trend,' sneers Severus. Hermione is momentarily taken aback when she realises that he's never told Lucius about his disability, and it seems that Lucius has been keeping secrets of his own.

'No, but when the sample for potentially life-threatening magical allergies includes six other former Death Eaters, all of whom have received treatment at St Mungo's, then the addition of two is statistically significant, don't you think?'

Both men glare at her. When she meets their ire with an interrogative look, they glare at one another.

Severus is the first to look away. 'It started with silver,' he says, swishing to the far side of the lab. 'Then aconite. It wasn't the ingredients by themselves, only when used in a potion. I was able to manage it for a while by writing the instructions on the boards and supervising instead of demonstrating, but after the Dark Lord's return, I finally reached the point where I could no longer tolerate being in the same room where brewing occurs without effect.'

'I had no idea it had been going on so long,' says Hermione. Severus's hands-off teaching style makes a great deal more sense now. 'When did you first notice a problem?'

'Shortly after I was appointed Potions Master at Hogwarts.'

Lucius has an unfamiliar expression on his face. It takes Hermione a few moments to recognise it as pity. Severus notices it too and makes a dismissive noise.

'Compared to hiding my true allegiances, concealing a magical allergy was simple.'

'I can imagine,' says Lucius. 'My own experience started in my seventh year at Hogwarts. I found myself feeling quite weak during the carriage ride to the school. In those years, Rebeus Hagrid was merely the groundskeeper, not the Care of Magical Creatures instructor, so I didn't know that it was the Thestrals that were causing the problem. However, I understood when I visited my father's stables over the holidays. He bred Abraxans, you see.'

Severus is watching Lucius carefully and nods, seemingly unconsciously. The puzzle pieces are falling together for him, as well.

'When he passed, I had to clear the Manor of his winged horses, Crups, and my late mother's Kneazle. The peacocks were all that remained, and I had to stop giving them magical feed. Even the house-elves made me feel weak, and I admit, I took out some of my frustrations on them.'

Hermione regarded him curiously. 'But you have house-elves now.'

'After the house-elf Dobby left my service, I noticed that the Hogwarts elves did not affect me in the same way that my own did. After sending one of my elves to investigate, I found that the Hogwarts elves had more than enough tasks to keep them busy, whereas I had a houseful of elves and considerably fewer domestic duties. Like the horses my father once kept, I realised that keeping the elves busy would make them less likely to cause me mischief, even if they weren't doing it deliberately.'

'So the idle elves acted like reservoirs of magical energy, which exacerbated your allergies?'

'That was my reasoning at the time,' says Lucius.

'Exactly what did you do to make your elves more magically active?' Severus's arms are crossed, but his expression is more curious than forbidding.

Lucius smiles. 'Do you recall your home being significantly less sty-like when you returned?'

'No.'

'You wouldn't. But I dispatched the elves to friends and neighbours to clean when and where they would not be seen.'

'Your closest neighbours are Muggles, Lucius,' says Severus.

'As if they would complain.'

Hermione begins to giggle. 'Lucius Malfoy's Clandestine Cleaning Service. Still, it's impressive that you solved the problem well enough to have never been sent to hospital with magical depletion.'

'Not in England,' says Lucius.

'And certainly not when one is harbouring a fugitive Potions master,' says Severus.

'You never gave any sign that brewing caused you distress,' says Lucius.

'That's because I always brewed your Replenishing Potions by proxy. I'm well enough as long as I don't touch the ingredients and protect myself from the fumes with a Bubble-Head Charm.'

Lucius looks at him disbelievingly for a moment and then begins to laugh. 'You were the one who taught my elves to prepare potions ingredients.'

Severus smirks. 'Did you really think the Cordon Bleu taught house-elves?'

Hermione clears her throat to keep from laughing, and it also serves to remind the men of her presence. "Isn't it interesting that you both began to exhibit symptoms shortly after joining Voldemort?'

It's a testament to time and their characters that neither flinches when she says the name.

"A correlation is not causation, ma petite," says Severus.

She smiles to hear d'Aubigny's affectionate nickname delivered with Severus's dry humour. "Of course not. But allergies produce broken magic, as Lucius describes it, as does this lost magic of de Sade's. Broken, or split. Might exposure to Voldemort's soul-splitting experimentation have detrimental effects on those closest to him?'

Severus frowns. 'Conjectural at best.'

'You make it sound like a disease,' says Lucius.

'Perhaps it is, in a sense,' says Hermione, a new thought occurring to her. 'Perhaps splitting a soul or separating a person from his or her magic creates something that the magical self finds anathema. In a person's attempt to destroy the residue, it begins to attack magic outside itself indiscriminately.'

'It sounds elegant. But so does Byron's description of the universe as nested crystalline spheres. There's no evidence that's what's occurring,' says Severus.

'Of course there's evidence — I'm here, aren't I?' Heremione runs her fingers through the curls that have escaped from her ponytail. 'Magical allergies are becoming more and more common since around the time Voldemort decided to shred his soul in unprecedented ways. What if splitting the soul is like splitting the atom? Fallout from the cataclysm can last for hundreds of years.'

'Who's Adam?' asks Lucius, looking confused. Both Severus and Hermione shush him.

'Think about the potential spread. Voldemort was in the Ministry. He was at Hogwarts. He lived in Lucius's home. He was in any number of places where he could have exposed people to whatever this is.'

'And de Sade's experiments took place in my dungeon,' says Lucius dryly. 'By that account, I should be the sickest of us all.'

Severus gives him a hard look. 'You spent the year that the Dark Lord lived in your house looking like death warmed over.'

'It's true that I was ill while the Dark Lord lived in residence. But I assumed it was caused by the presence of that beastly snake. If Hermione is correct about the split soul being the cause of the problem, the effect would have been twofold.'

'It must have been awful,' says Hermione, sympathetically.

'It was neither the first nor last time I have been grateful for Severus's friendship.'

Hermione feels a hot flare of indignation on their behalf. Voldemort's experimentation claimed far more victims than she had ever supposed, and to drain people of magic is an unforgivable violation. And the allergy has not only interefered with their magic but also the men's fundamental relationship to the practise of magic, since Lucius can no longer abide the creatures he once loved, and Severus cannot brew.

'I want to make the potion,' she says. 'If there's any way I can treat this, I want to start work on it as soon as possible.'

'It's late, my dear. I'm afraid I'm not as young as I once was,' says Lucius, sliding comfortably down in his chair by the fire.

Hermione looks at her half-full glass of Port and sighs. She catches Severus's eye. 'Tomorrow, then?'

To her surprise, Severus sits down next to her on the settee and meets her gaze levelly. 'You know there's no chance of success tomorrow. The textual sources are too vague and disparate, the theoretical framework is unclear at best, and you simply haven't the brewing experience. It's going to take months of research, planning, and experimentation before we have sufficient data on to move forward with testing.'

She puts her hand over his and presses it. 'I know that. I've never thought tomorrow would be the end, though I had hoped it might be the beginning.'

He looks at her, his eyes warm despite the stillness in his face. 'I think that much, at least, can be arranged.'

~o0o~

Her posterior is completely numb, and she can't tell if it's from the hardness of the dungeon floor or its inherent chill. But the sweet taste of Felix Felicis is still warm on her tongue, and Luna has been wonderful company. For the first time, she understands that behind the outlandish theories is a valuable ability to speak the truth, and Hermione feels lucky to see this side of Luna.

The door to Professor Snape's chambers is resolutely closed, as it has been for the past hour, and Hermione begins to wonder if the Felix Felicis Harry left them is sufficient to keep Draco Malfoy and his plans at bay. And then she hears it — the sound of feet pounding down the stairs and then slapping loudly against the stone floor.

To her surprise, Professor Flitwick, his face bright red with exertion, tears past their hiding place at a speed she didn't know the tiny man was capable of and pounds on Professor Snape's door.

'Severus!' he squeaks, breathing hard. 'Severus, you must come at once! They're here!'

The door opens quickly to admit him and shuts before Hermione and Luna have the chance to move from their alcove. Before they can knock, Professor Snape opens the door to reveal Professor Flitwick lying on the floor, unconscious.

'Death Eaters in the castle.' Hermione isn't sure if it's her own mind connecting the dots or Felix's suggestion, but she feels the truth of her statement.

'They got Professor Flitwick,' says Luna sadly.

Professor Snape's face is as still as marble and as pale. 'So it would seem. Filius isn't well. See to him now if you can, and take him to the Hospital Wing when it's safe. And above all, do not make yourselves targets.'

Professor Snape brushes past Luna, but Hermione places her hand on his arm. 'Is there anything I can do to help?'

'Don't touch me,' he whispers, his voice flat and hard.

In a glance she understands that her hand is resting over his Dark Mark, and there is anger on his face, but rather than shake her hand off, his scowl seems troubled, and it's not so much directed at her as at the wall behind her. A ball of apprehension settles in her stomach. The situation must be dire indeed if Severus Snape hesitates to face it. She squeezes his forearm, and his hand curls into a fist instinctively.

'I believe in you,' she says quietly, and then Felix is there, pushing her forward on to her toes.

She seizes the front of his robes and kisses him full on the mouth.

She doesn't need Felix to tell her to close her eyes or open her mouth as he gasps in surprise or enjoy the moment when he begins to kiss her back. His lips are strong, his mouth is warm, and he tastes savoury, with a hint of herbal bitterness. His arms encircle her so tightly that she can't breathe, but she doesn't care. She buries her fingers in his hair and holds him as tightly as she can. He's breathing hard through his nose, desperately clinging to her and this strange place where she can offer him comfort and he can accept it, just once, before confronting something so terrible that neither wants to contemplate it. She has no idea how long they stand there holding one another until his arms release her and his hands go to her shoulders, gently pushing her away.

When her eyes come back into focus, he is looking at her as though he's never seen her before, and in his face there is such naked anguish that she longs to take him in her arms again, but both she and Felix know it's not a good idea. And then his face is the same impassive mask that she knows too well, and he flees down the corridor.

Hermione watches him go, her heart pounding in her throat.

They will not speak again for eighteen years.

~o0o~

Ninteen years and two hundred twelve days later, Hermione steps off the broken end of the Pont Saint-Bénezet and approaches Lucius's home once more. A stunningly white peacock and silver peahen peck between the cobblestones encircled by several dark brown chicks. When the male spies her, he fans his tail, and to her delight, it sends blue-white sparks dancing towards her, and she laughs, delighted by the display's frivolous beauty.

She pauses at the hitching post and sets her satchel on it, checking for the umpteenth time to ensure that she's remembered the letter from The Journal of Alchemical Healing, which she's already committed to memory but doesn't want Severus to know it.

Dear Healer Granger,

In re: your paper 'A New Paradigm for Treating Fallout-Induced Magical Sensitivity,' which has been accepted for next month's issue, along with Laurence d'Aubigny's paper Mechanisms of Magical Decay and the appendix of historical documents from the de Sade estate, we took the liberty of sending the abstract to our subscribers, since we cannot justify making the ill wait any longer than necessary for treatment. We have been overwhelmed by the response. Not only have we received the largest number of single-issue pre-orders in our publication's history, we have also been inundated by requests from Healers for your protocols. We hope that, given the dire state of those afflicted with magical allergies, you and your co-author will consent to us providing the recipe to healing practitioners prior to publication and have enclosed the necessary release forms. We eagerly await your response.

Yours sincerely,

Messrs. Jameson and Jenson
Eds.

She smooths the parchment flat between the leaves of her book and returns it to her satchel, and when she looks up, she sees Lucius watching her from the library window. She can't see his face clearly, but the gesture he uses to summon Batty is unmistakeable, and she knows there will be champagne momentarily.

She can't control the little leap her stomach executes when the front door opens, and Severus appears as himself. She has an odd moment of surreality as she sees Professor Snape's characteristic scowl settle upon his face, but his mouth twitches, and he is her Severus once more.

Abandoning all pretence of decorum, she hoists the satchel over her shoulder and runs to him. His lips are warm on her forehead, and then on her lips as she raises her face to him. He smells of freshly-chopped herbs and the medicinal scent of juniper. After kissing him into an impressive state of smugness, he takes her hand, and together they cross the threshold of Lucius's chateau.

She has no idea what lies ahead any more than she has at any point in her life, but the auspices are favourable indeed.

~o0o~

The End

~o0o~

Author's Note: I am as always, indebted to Mr. 42's beta-reading prowess and eternal patience and Bluestocking79, whose comments have improved this story beyond the lot of mortals. The title is taken, sort of, from Hercule Poirot. "Only by interrogating the other passengers could I hope to see the light, but when I began to question them, the light, as MacBeth would have said, thickened." The long quotation is really from de Sade, though I have my wicked way with him later while referring to magical content.

This story was written for the SSHG Exchange combining the following prompts: 1. Aversion to silver and aconite prevents Snape from brewing Wolfsbane, so Hermione must do it. She behaves strangely and he wants to figure it out. 2. Hermione discovers something that convinces her Severus is a loyal Death Eater. She is fascinated despite herself. 3. On holiday abroad after the war is over, Hermione discovers Snape and a new and unexpected threat to the wizarding world (bonus points for bringing in Lucius).