a/n: Another humongous thank you to AFamiliarWitch, my beta, who really deserves an award, at this point, for putting up with me for so long. Like a Nobel for patience.

It was mid-February. Six weeks into a new term.

Half the castle had been eaten by a forest.

All the centaurs were dead.

The Deputy Headmaster was missing.

And Tom Riddle was going to kill Cornelia Fowler.

The day hadn't started that way. At first, it was just going to be blackmail or something similar. Then, sometime in the evening, the blackmail plan was promoted to torture. By the end of the night, it was murder.

But before any of that, there was the nurse.

Dippet's solution to the Valentine's Day incident was to place extra protections on all potions stores in the castle and to require all internal letters to be sent to his office for inspection and delivery. He also decided, for some unfathomable reason, that those involved in the incident should be evaluated by the nurse. Slughorn had insisted this wasn't necessary, but he was ignored.

In the morning Tom received a note, delivered via noticeably unhappy caretaker, that instructed him to report to the Hospital Wing at three o'clock in the afternoon.

Thinking it would likely be a quick physical examination and some questions, he decided to get it over with. So, at three o'clock he entered the Hospital Wing, where the nurse, Madam Sable, was waiting for him.

"Thank you for coming, Professor," she said. "If you wouldn't mind just putting your wand in here."

"I'm sorry?"

She was gesturing toward a small cabinet hanging on the wall. "It will be locked. No need to worry."

"I'm not giving you my wand."

"There are no wands or magical objects allowed in the infirmary, I'm afraid, outside of those with medical purposes. And as my office is inside the infirmary, you will need to relinquish your wand."

"Since when? And what, exactly, are 'medical purposes?'"

She ignored him. "If you wouldn't mind," she repeated, gesturing again to the cabinet.

He did not move.

"Alternatively," she said, "should you wish to do so, you may keep it on your person. But please note that there is an unpleasant flesh-burning charm protecting the area, and I am told the experience is agonizing."

Tom had never spoken to Sable before, and found that she had a kind voice, but was horribly matter of fact with it - like an auror that was smiling politely and putting a hand on your shoulder while simultaneously telling you that you were being sent to Azkaban for the rest of your life and would you like a cup of tea to cope?

He briefly considered simply walking out, or stunning her and then walking out, or killing her and then walking out. Whatever he was going to do, he had to do it now.

"You should also note," Sable added, "that performing unwarranted magic in any part of the Hospital Wing will result in a similar outcome."

How convenient.

It was just a physical examination and some questions. He doubted anyone would attack him in the middle of an infirmary. He could likely go a few minutes without his wand.

No. He would never place himself in a position like that. No possible circumstance existed that would justify him being unarmed for any length of time, including this one. What if the nurse needed to be subdued?

Why would the nurse ever need to be subdued? It would cause more alarm to refuse relinquishing his wand than it was worth. And he had been practicing recently with more physical forms of violence. Perhaps-

"Professor?"

"Fine," he spat, reluctantly handing her his wand and immediately regretting it, suddenly feeling like every enemy he'd ever had was going to be on the other side of the infirmary doors.

"Thank you." She took it and placed it carefully inside the cabinet, which she shut and locked with her own wand.

Hypocrite.

"I'm assuming you have a special 'medical purposes' wand, then?"

No response.

She was very adept at making a person feel completely ignored, even while interacting with them. She opened the doors to the infirmary and led him toward the back, where her office was. The room was clean and white and largely empty, with nothing in it except two chairs, a small cabinet, and a desk with a quill and ink well on it. They sat down and she took out a long piece of parchment.

She dipped her quill in ink, scratched something on the top of the parchment, and then said, "I would like to start by reviewing your symptoms. Are you still having hallucinations?"

"No. They stopped when Professor Slughorn neutralized the poison, which I believe he told you-"

"What about voices? Do you still hear voices?"

"No."

"Any feelings of fear or paranoia?"

"No."

"Are you sure?"

"Yes."

"I noticed that you were hesitant to relinquish your wand. Do you think that perhaps-"

"I am not paranoid."

Her face was blank. Completely blank. No emotion whatsoever. She nodded as she wrote, scratching far too many words onto the parchment for what little interaction they'd had.

"Did you have any of these symptoms before the incident?"

"No."

"Excellent. Thank you."

Maybe that was it. Maybe they were done and he could leave.

"I will now begin the psychological portion of the evaluation."

"The what now?"

He was really hoping she did not just say what he thought-

"The psychological evaluation," she repeated absentmindedly as she turned the parchment over and wrote something at the top again.

"I was not told I would be receiving a psychological assessment of any kind," he informed her.

She didn't bother looking up from her writing as she responded. "The poison you were exposed to caused symptoms of a psychological nature. We need to be certain that no one has been permanently adversely affected by it."

"And what exactly will this evaluation entail?"

"I will ask you questions about certain personal and professional aspects of your life to determine if any issues exist that warrant further treatment."

No.

This was not going to happen.

He had no doubt he could lie his way through it without a problem, but he did not want any record of anything "personal" to exist in reference to him anywhere for any length of time, even if it was mostly lies. He would simply give her a nice, happy memory of evaluating a completely normal person who gave completely normal answers. That would be the easiest-

He did not have a wand.

Unless he hit her over the head with a chair and fled the Hospital Wing, he would just have to sit through it and come back later tonight to destroy everything.

Although, the chair thing wasn't a bad idea…

No. Far too risky. This was merely an exercise in lying. He could handle it. Spit out whatever was already on file, then lie about the rest. It would be fine.

It was doomed from the start.

"May I have your full name, please?"

"Why do you need to know my full name?"

Now he definitely sounded paranoid.

She did not answer, but started to write on the parchment, more long sentences in thin handwriting. He couldn't read it from where he was sitting.

"What are you writing?"

"Is there a problem with your name?" she asked, ignoring his inquiry.

"What? No."

"Do you dislike your name?"

No, he did not dislike it. He hated it. But… was this an evaluation question? Was she writing down that he was paranoid and secretive because he didn't want to give his name? Or was she just curious? He couldn't tell – her face was like stone. "It's fine," he said lamely.

"Then, full name, if you please."

This was starting out wonderfully. "Tom Marvolo Riddle."

"Is that short for 'Thomas?'"

How the bloody hell was this relevant to anything at all? "No."

"No?"

"I do, in fact, know what my name is, and it is not 'Thomas.' Either that or I spent my entire life grossly misinformed."

"I see." She had started to write again.

He'd never been psychologically evaluated before. Even when he was younger and had so thoroughly annoyed and frightened the Matron that she felt her only line of defense was to threaten to throw him into an asylum. There was no way to tell what Sable was analyzing – his responses? His behavior? Both?

Were hesitant answers a bad thing?

Was he already marked down as a psychopath somewhere on that paper?

It didn't matter. He'd be destroying it anyway. But, still…

"What are you writing?" he demanded.

"Age?"

"Twenty-four."

"Birth date?"

"December thirty-first. Nineteen twenty-six."

She wrote. Multiple sentences, from what he could tell.

"Thank you. Let's start with family, shall we?"

"What?"

"Parents' names?"

"Mother was Gaunt, father was Riddle. Hence the last name 'Riddle.'"

"Are they alive or deceased?"

"Deceased."

"Were you close with them?"

"No."

"Any siblings?"

"No." Good lord. He could not imagine what that would be like.

"And what is your blood status?"

"I fail to see how that is relevant."

She tilted her head to the side slightly, examining him in a way that somehow felt even more intense than Legilimency. It was like her eyes looked right through him, through the wall, through the castle, and out into eternity. Then she started to write again.

"What on earth are you writing?"

"Why don't you think your blood status is relevant?" she asked after finishing her note.

"Because it has nothing to do with me being adversely affected by a poison for a single day, which is the reason I am here."

"I see." She nodded, took notes, gazed at him some more. "Are you sure it's not because you don't wish to talk about it?"

He glared at her in response.

"It's no matter," she said. "I'm sure your status is on file, here." She gestured toward the small cabinet in the corner. "But it would be easier if…"

He glared at her some more. "Half-blood," he muttered, making note to destroy the cabinet too.

She wrote it down. "And which side-"

"Mother."

Wrote it down.

"And where were you born?"

"London."

It was a longer note this time. "London" had six letters, not eighty. What was she playing at?

"I see. And where in London?"

There could not have been anything less relevant to brief poisoning than where he was born. But arguing relevance clearly wasn't going to get him anywhere. "Lambeth," he said.

"I see."

As she wrote at length about whatever psychological meaning Lambeth had that likely made no sense whatsoever, he wondered what she would try to do to him if he just got up and attempted to retrieve his wand from the waiting room.

"Were you raised in a wizard neighborhood?"

"Yes, in one of the many wizard communities that exist in Lambeth."

"So, yes, then?"

"No."

"I see."

If she said "I see" one more time he was going to rip that quill out of her hand and stab her in the neck with it.

"So was it a Muggle-"

"Orphanage."

"I see."

Fucking hell.

"Would you say you had a happy childhood?"

He made a face before he could stop himself. "Allow me to repeat my previous answer: orphanage."

"That would be a no, then?"

He stared at her.

She made a note. Her lack of sympathy was impressive.

"What do you think contributed the most to your unhappy childhood? Other than being raised in an orphanage."

"I'm not sure. It might have been living in the city, or being poor, or maybe it was the massive, violent Muggle war I had to live through."

"Right," she said quietly.

"Right," he spat back.

"I would like to revisit blood status for a moment," she said, ignoring his growing impatience.

"Why?"

"Do you consider blood purity to be an important characteristic of a person?"

He didn't know how to answer that. Did the Heir of Slytherin consider blood purity to be an important characteristic of a person?

"No," he lied.

"You seem hesitant. This is a safe space. Please feel free to discuss-"

"No."

She looked at him carefully, her face still blank. It was becoming rather unsettling. He'd seen corpses with more emotion.

"Let's talk about relationships," she said after a while.

"Let's not."

"What is your marital status?"

He was extremely annoyed now. "Single."

She took note. "And is that by choice?"

"What the hell does that mean?"

"Are you currently looking for a partner?"

"No."

This time, she did not write down the answer. Instead, she stared at him for what felt like ages, her eyes unmoving, and he was beginning to wonder if she really was trying to read his mind. "Interesting," she said.

"Why is that interesting?"

"Any current sexual relationships?"

"No. Why is that interesting?"

"Have you ever been married?"

"No. Why is that interesting?"

"What have your past romantic relationships been like?"

If he'd had his wand he would have cursed her five times over by now. "'Nonexistent' is, I think, the most accurate description."

He knew he was going to get notes for that one. Maybe he should have lied a bit more. Made up some prolific romantic history with a string of forlorn lovers. That was probably more normal than not having any relationships at all whatsoever.

"Thank you. I'll need to know a bit about your education and professional background. Year of graduation?"

Dear lord. This was never going to end. "Nineteen forty-five."

"Would you say you were a high-achieving student?"

"Yes."

"In what way?"

"I achieved a high number of things."

He could have sworn he saw her eye twitch a bit. "I mean, how were your marks?"

"I never received anything below 'Outstanding.'"

"Really? That is quite impressive." She seemed suspicious. What he said might have sounded a bit arrogant, but it was also true. She could look it up in her tiny cabinet of secrets if she didn't believe him.

"Did you have many friends in school?"

If you could call them that. "Yes."

"Were you often disciplined for bad behavior?"

"No."

"Previous place of employment?"

Borgin and Burke's Shop of Moderately Disappointing Horrors. "Borgin and Burke Alternative Magical Supply and Trade Company."

"Did you leave said place of employment under negative circumstances?"

He reminisced briefly about the lovely mess he'd left his bosses on that last day at the shop. He wondered what ever happened to them. Dead, hopefully. "No."

"Have you ever been terminated from a place of employment?"

"No."

"Do you enjoy your current position? Are you happy in your career?"

It was extremely, agonizingly difficult not to laugh hysterically at that. "Yes."

"Thank you, Professor. We are almost done. Please answer these next questions truthfully."

Was she suggesting he hadn't been answering the previous questions truthfully? Because that would have been accurate.

"Do you suffer from any sort of addiction? Potions, substances, food, sex, that sort of thing?"

Did fantasizing about murdering people count? "No."

"Do you ever have thoughts of harming yourself?"

Apparently, since he thought deciding to become a teacher was a good idea. "No."

"Do you ever have thoughts of harming others?"

Every single day. "No."

"Do you feel that some people deserve to be punished?"

Yes. "No."

"Do you feel some people deserve to be rewarded? With wealth and success and such."

Yes. Tom M. Riddle, for sitting through this nightmare without killing anyone. "No."

"If you could describe yourself in three words, what words would you use?"

He blinked stupidly at her. "What? I don't understand the point of that."

"Just try."

"No."

The slight, almost imperceptible shadow of an emotion briefly passed over her face, and he was fairly certain that emotion was annoyance. "I must insist," she said.

If he responded with positive traits, he would sound arrogant. If he responded with negative traits, which he would never do in any scenario the universe could come up with anyway, he would sound weak. What neutral traits were there?

"Human," he said.

There was definitely annoyance in her face now. "And?"

"Male."

"Professor Riddle, do please try to answer the question."

"I am answering the question."

She studied him for a moment. Then she set down her quill, opened a drawer in her desk, and pulled out a square piece of paper. "This is what I use when I evaluate the younger students, Professor. Perhaps it will assist you in answering the question if you are having difficulty."

There was no hint of mockery or condescension in her voice, which somehow made it even more offensive. The paper had boxes with words in them like "confused," "sad," "clever," "afraid," and "ambitious," and each one was paired with a poorly drawn face.

He was going to kill her. "I do not need-"

"Brilliant. Then allow me to ask the question again. If you could describe yourself in three words, what words would you use?"

She was a monster. A clever, intimidating, corpse-faced monster.

"Intelligent," he said.

"And?"

"…Discerning."

"And?"

He sighed and glanced quickly at the paper with boxes on it. "Ambitious," he muttered.

"I see."

And then she wrote. And wrote. He sat there for two minutes, three, five…

"Thank you," she said after finishing her notes.

"Please tell me we're done."

"Not quite. I just need to examine a few things." She came around the desk and bent down to look at him, sticking her very brightly lit special medical wand in his eyes, switching from one to the other. Strangely, it reminded him of something.

Several thoughts crossed his mind at once and merged into a single, simple idea. A realization.

Cornelia.

Cornelia had poisoned them.

Cornelia, who would have no reason at all to talk to him or seek him out, had been standing in front of his office that day, during his… episode, as if she had been waiting for him to show up unexpectedly while he should have been teaching.

And when she saw him, she had examined him. She didn't glance at him, make a face, or look concerned. She examined him. Just like the nurse.

He didn't know why, or how, but he was certain Cornelia was responsible for the poison. And he was willing to bet she had something to do with those vials of whatever-the-hell substance that were making their way through the student population, too. Vulnerable, impressionable children walled inside a castle for ten months were undoubtedly a captive market.

And, if he was right, then she was the reason he had been forced to sit through a bloody psychological evaluation.

She would pay dearly for that.

"Professor?"

"What?"

"I asked if you've had any trouble hearing lately. Twice."

"No."

Sable took his wrist and held it. "Your pulse is a bit fast."

"Is it?" Feeling murderous probably had that effect.

Then she felt his forehead with the back of her hand.

"I never had a fever," he told her.

"No, but you look very pale."

"I'm always pale. Are we done?"

She gave him one last blank, corpse-like look.

"Yes," she said, returning to her desk and rolling up her parchment. "That will be all for now."

He was already leaving.

"However, Professor, I do wish to recommend a course of counseling to address-"

He slammed the door behind him.

He went straight from the Hospital Wing to his office, scrawled a quick note on a piece of paper, then rushed to the Owlery to send it. The letter told Lestrange to hand over everything he'd found on Cornelia Fowler, regardless of his progress. If there was enough evidence, they might be able to expose her as the criminal she surely was, which would be a fitting response to her poisoning him.

Unfortunately, the situation was far worse than he had assumed.

They met in the Hog's Head that evening, despite Lestrange's insistence that one should never visit the same pub twice.

"I'm telling you, we're being watched."

"Lestrange, I do not have the patience to deal with your unique brand of paranoia right now. Just give me the information."

He pulled out of his robes a large package wrapped in brown paper. He set it on the table, glanced around nervously, untied it slowly, removed several charms he had apparently placed on it, unfolded the wrapping-

"Any time, Lestrange."

"Sorry, boss. Can't be too careful." He chuckled as he opened the first folder. "I thought maybe you were doing a sort of stalking thing. You know, some weird way to get to know a pretty woman."

Tom sighed. "Yes, because that is definitely the sort of thing I would do."

"Hey, I don't judge. To each his own, or whatever."

"That is not what I was doing."

"You don't have to explain it to me. That's your business."

"Jesus Christ, Lestrange. I was not-"

"Anyway, she is much more interesting than you said. Hope she doesn't turn out to be an enemy. That would not end well for you."

"She already is an enemy."

"That won't end well for you."

"Thank you for that assessment."

There were folders upon folders of pictures, news clippings, and official documents. Whatever this was, it went far beyond selling illegal potions to students.

It appeared that Cornelia Fowler was not only a criminal, but a crime boss, as well as, possibly, an infamous dark witch and part-time guerrilla terrorist.

First, Lestrange had found evidence that she had been forced to cut her research sabbaticals short at both Castelobruxo and Uagadou for "unknown reasons," but separate news stories from the same time periods showed significant stores of expensive and rare Potions ingredients and equipment being stolen, and several members of the faculty disappearing without a trace, only to be found months later. In pieces.

Then there were the undeniable links between Cornelia and a well-known Dark witch by the name of Reyes, who had been active in America, gaining followers and building networks, until she disappeared two years ago.

There was also the Muggle photo of a woman who looked remarkably like Cornelia posing with a group of Paraguayan soldiers during some recent civil war, dressed in a military uniform and carrying a large gun.

He was not terribly surprised by the nature of her activities, but the scale was impressive. His desire to take over wizarding Britain was suddenly starting to feel rather small.

"I was in Florida when I got your letter," said Lestrange, "poking around a few warehouses there. That's where she's been, you know, for the last month."

"Florida?"

He nodded. "I'd been hoping to capture and interrogate a few of her lackeys that worked on the docks, but…"

"But?"

"They're all Muggles. Makes it more difficult."

"I take it she has no aversion to mudbloods, either?"

"Loves 'em. A proud mudblood herself, from what I can tell."

But it didn't quite make sense. If she was already so powerful and well-established elsewhere, why would she bother coming here? What did she need from Hogwarts? It wasn't like she had-

She.

She.

"I have to go," he said, gathering up the files and tossing Lestrange's payment on the table.

"Boss, don't engage. If she's this Reyes person, then her dueling skills are unmatched on at least two continents, maybe three. If you even attempt-"

"Yes, thank you. I get the idea. Give me your knife."

"What?"

"Your knife. I need to borrow it."

Lestrange looked bewildered. "When have you ever used a knife?"

"Just give it to me."

"It's just a knife. It ain't magical or anything."

"I don't need it to be magical."

"Ah." Lestrange smiled. "Proper fun, then."

Without wasting time, he made his way back to the castle and headed straight for the Room of Requirement.

The impostor was hers. He had to be. She was certainly conceited enough to think that she could plant a false Dumbledore at Hogwarts without anyone noticing, and she likely had the knowledge to give him a disguise that could not be removed with magic.

And he wouldn't put it past her to have killed the real one.

More importantly, if she was the "she" that Dumbledore kept talking about, then she had the Sword.

He hadn't returned to the Room in over a week, mostly because he was too busy with teaching, but also because he didn't think he would accomplish anything if he attempted another interrogation unless he beat the man to within an inch of his life.

He was certainly willing to do that now.

The prison cell had expanded since his last visit. It now included an entire wall of books, several new pieces of furniture, a fireplace, a much larger window, and a small, decorative plant that sat in a pot in the middle of the table.

And the prisoner himself was sitting in a large armchair by the fire, reading and drinking from a wine glass.

"How are you doing this?" he demanded, taking note of the soft, red curtains that adorned the window.

"Oh, it's you," Dumbledore mumbled, not bothering to take his eyes off his book. "Doing what?"

"How are you- Never mind. Tell me who 'she' is."

"She?"

"You have mentioned a 'she' several times now. Who is 'she?'"

Silence.

"Is her name Cornelia?"

He was hoping for a look of fear, or surprise, or an "oh no, my secret is revealed!" face. He got none of those.

"Who?"

"Cornelia Fowler. She's your boss, isn't she? The one you so humbly serve? Sent you here to dispose of the real Dumbledore, no doubt, and fool the rest of us into believing that everything was normal."

Dumbledore set down his glass and closed his book slowly. "Can't say I've heard of her."

"You keep saying 'she.'"

"I do. Mostly because it annoys you to no end."

Tom raised his wand and a thousand black ropes flew out of the end of it. They streaked across the room and wound themselves tightly around the impostor like vicious, determined snakes, tying him to the chair so that he was unable to move.

"Please kindly remember," Tom said quietly, "that you are my prisoner. Not the other way around." He made a movement with his wand and the ropes tightened even more.

"Yes, you- you are making that quite- quite clear," Dumbledore stuttered, struggling to breathe.

The Room had decided to join in the fun, apparently, as a layer of thick, heavy chains had suddenly appeared on top of the ropes.

And before the idiot could find some unique, magic-defying way to escape, Tom put Lestrange's knife to his throat.

"Now," he said, feeling the familiar sense of calm that came from being fully in control of a situation, "I'm going to ask you one more time. Who is 'she?'"

Dumbledore mouthed something incoherent.

"What?"

"I can't say."

"I'm sure you can."

He went silent, but Tom wasn't having it. He pressed the knife hard enough to the man's skin to draw blood.

"I- I don't work for Cornelia."

"Who do you work for?"

"Whom."

"What?"

"It's- it's 'whom,' not 'who.'"

"I'm holding a knife to your throat and you're correcting my grammar?"

"A risky move, I'll admit."

He tried one more time. "Whom do you work for?"

"You," the impostor croaked.

"What?"

"I sup- suppose I work for- for you, now."

Tom drew the knife back the tiniest bit so that the idiot could still feel it while being able to talk. "Explain."

"If I don't tell you whom I work for, you will-" he wheezed loudly, "-will kill me. If I do tell-" (wheeze) "-tell you whom I work for, she will kill me. Unlike my counterpart, I am far more dedicated to self-preservation."

"Except when it comes to grammar, apparently."

"We all have our priorities. Anyway, it appears my safest course of action may be to change allegiance."

It was almost disappointing how un-Dumbledore-like the man was. Then again, Tom did not technically know how the real Dumbledore would react to a knife being held to his throat, so maybe this was an accurate portrayal.

And then he was suddenly very curious about what the real Dumbledore would do with a knife to his throat.

"And how does having your evidently changeable allegiance benefit me, exactly?"

"W- well," the impostor wheezed, "I have abilities that far surpass y- most of the wizards here."

"And?"

"And I pass successfully as the Deputy Headmaster of this extremely disorganized place-"

"As long as no one talks to you long enough to find out what a complete arse you are."

"True. I also know where the Sword is."

"Where is it?"

"Well, I can't exactly tell you."

Tom was drawing blood again. Worse, this time. It had started to drip down the front of the impostor's robes. "You will tell me. Right now."

"I can't. Even if- if I wanted to. I am Bound."

"What do you mean 'bound?'"

"I cannot reveal the name of my… former employer, nor can I reveal her location, which also happens to be where the Sword is. To do so would sentence me to a violent, painful, and somewhat immediate death."

"An Unbreakable Vow?"

Dumbledore laughed between wheezes. "Imagine an Unbreakable Vow with the ability to not only kill the person that breaks it, but torture them into insanity first. And there are no limits to what stipulations are given. It is not an agreement between two people. It is a Bond between a master and a servant."

"So, you're a servant?"

"In a manner of speaking. She could break the Bond now, if she wanted. I expect she'll consider it, since I haven't reported back in a while..."

"I fail to see how someone who is trapped in a terminal agreement with another person could possibly be useful to me."

Dumbledore was looking weary now. "I can't say her name, I can't say her location, but nothing is stopping me from being a party to… other agreements. Or vows."

"That is hardly a change of allegiance. And I do not make Unbreakable Vows. I do, however, issue contracts."

"Contracts?"

"Think of them as something between an Unbreakable Vow and your ridiculous death bond. Not quite as versatile or amendable, but just as painful and deadly."

"Brilliant," Dumbledore said flatly.

"But why should I believe a word of your ludicrous 'Bond' story? How do I know that this isn't all a ruse? That you're not just placating me until you can escape or strike back?"

"Will the contract not appease you?"

Tom thought for a moment. "Give me something now. Prove to me your usefulness before I waste any more time keeping you alive."

"You are looking for Cornelia, yes?"

"No, I just came in here shouting her name at you for fun."

The impostor chuckled. "Fortunately, I have only met Cornelia once. And during our brief conversation – in which she had used the most colorful term 'self-righteous prick' to describe me – I did manage to read her mind."

"And?"

"Her head was filled with thoughts about some experiment. 'Launch the experiment,' 'monitor the experiment,' and something about Valentine's Day. I'm not sure what the date is currently, since I am being held hostage, but-"

"What else?"

"The only other thing I caught was that, after the experiment, she had intended to dispose of what she called 'nonessentials,' starting with her immediate supervisor. She was contemplating the most efficient and… entertaining way to kill him."

"Supervisor?"

"Yes. You may want to check on him."

He hadn't seen Slughorn in days, which was highly unusual, and he wanted to kick himself for not noticing it.

There was a chance that the impostor had read his mind and was attempting to distract him just to keep from being interrogated further. But it did not hurt to check and make sure Slughorn wasn't lying dead somewhere. The man was still useful in most respects.

He wasn't in his office, or anywhere in the dungeons. Tom tried his quarters next, already picturing in his head the scene of a recently murdered Slughorn, followed by the immensely satisfying scene of himself killing Cornelia slowly and painfully.

"Horace!" he yelled, banging on the locked door.

There was a faint murmur from inside.

He removed the door with a spell, a bit more forcefully than he had intended, and found Slughorn on the floor of his own living room, shaking and holding himself, but still alive.

"What happened?" Tom demanded.

He smiled weakly. "Oh, I just have a few health issues I need to take care of." He sounded like he was trying to be his normal, cheery self, even as he appeared seconds away from losing consciousness.

"I have to admit, Horace, you're not looking well."

He frowned. "Is it that obvious?"

"Well, you are currently lying on the floor, sweating and shaking and mumbling to yourself. So, yes, I would say it is. What happened? Were you attacked?"

"No," he said as Tom pulled him to his feet and helped him to the sofa. "I just- I was fine… and then… I wasn't."

"You seemed alright on Valentine's Day."

"Oh, well that's good, at least. I don't remember Valentine's Day, but it's nice to know I was conscious for some of it."

Tom looked around and all he saw were vials. There were empty vials on the coffee table, in an ashtray, in the rubbish bin, on the floor… They were everywhere. "Might your current state have anything to do with those small vials of liquid you've been carrying around and that are now decorating every inch of your flat?"

He looked ashamed. "It might."

"Where did they all come from? And what are you doing with so many of them?"

"I was looking for… But they're all empty." He grabbed a couple of vials from the end table nearest him and turned them upside down. "I thought maybe I'd find a few drops here and there…"

"How did this start?"

"They just showed up one day, last summer. At my door. A whole carton of them."

"And you just started taking them?"

"Well…"

"You're the Potions Master. Surely you thought to test the random substance that suspiciously showed up on your doorstep before blindly ingesting it?"

Slughorn squinted his eyes as if he were trying to recall something. "I don't remember... why I didn't..."

This had the unmistakable signs of the Imperius Curse. Or memory modification. Still, given what Tom knew about Cornelia now, Slughorn was probably lucky to be alive.

"I did try to stop, but I couldn't. I just couldn't."

"So, you're addicted to it?"

"No, no. It's not a drug. It can't be. I have never- I would never-"

"Right, but you still have no idea what it is. So, technically, it could be."

"You are not helping me feel better."

"But why didn't you-"

"Look, I don't know," he said, sounding frustrated. "It would show up at my door and I would take it and... and then everything would be wonderful for a while. But I needed more and more just to be able to function-"

"Yes, Horace, that is how recreational drugs usually work."

He sighed and shook his head. "Dear lord. I might as well be a tramp living on the streets of Knockturn Alley."

Tom told Slughorn to stay in his quarters, deciding not to make his condition even worse by mentioning that the Potions Understudy might try to murder him at some point. The man already looked on the brink of death.

He put the door back into its frame and covered it with protective charms, wondering why Cornelia would bother to turn Slughorn into an addict if she planned to get rid of him anyway. Perhaps Dumbledore had been mistaken. Or maybe the "entertaining" part of her killing him was watching him descend into withdrawal-induced madness first.

He was going to kill her.

When he finished the charms on the door, he made his way out of the dungeons with the intention of finding and slowly torturing Cornelia until she confessed to every crime she'd ever committed, and then torturing her some more before the satisfying finale.

But she found him first.

He had just passed the staff room when he saw her standing in front of the doors to the Great Hall, staring at him with a big, satisfied grin on her face. She had a large bottle in her hand.

He pulled out his wand, but before he could do anything, she threw the bottle onto the ground. It shattered into pieces, releasing a thick, purple mist that filled the entire area in seconds, moving so quickly that it was impossible to avoid.

He attempted to curse his way through it, pushing toward the Great Hall to catch Cornelia before she could escape, but nothing could dispel it. Before long, her triumphant, smiling face was shrouded behind a cloud of purple fog, and she disappeared.

And then everything disappeared.