Harry James Potter was in his second year when he first met Mitsuki Oto.

'Creepy,' was what many of the students called him. Conversely, others called him attractive or even pretty. Harry wasn't sure what counted towards either, but if asked, he would have said that he was pretty sure both descriptors applied. It was the eyes, mostly. Yellow and slit, they were just weird.

Dr. Oto, he insisted on being called, was on loan from a little-known Japanese institute to learn about recent advances in healing in the United Kingdom, and Europe in general. To that end, he would be splitting his time between St. Mungo's and Hogwarts' hospital wing. At least, that was the official story that they were all told.

("What's St. Mungo's?")

("A wizarding hospital in London, Harry, honestly. Professor Snape has mentioned it at least three times when he tells us to pay attention if we don't want to end up with strange injuries like some of his former students.")

Harry had no idea what the truth was, but he actually did listen when Hermione started history-gossiping upon hearing the mention that Dr. Oto had chosen Hogwarts due to family ties, whatever that meant.

"The Oto family they…" Hermione struggled to come up with a good explanation, for once. "Okay, do you know about the Medici?"

"No."

"Never mind. The Oto family has been funding public works projects, especially schools, for well over a millennia. Their influence can be traced back all over the planet for most of written history." Hermione's eye glittered. "But only the current head and heir apparent ever hold the Oto name, and they're really insular. They helped fund the very creation of Hogwarts! Even Merlin wrote about them in his memoirs, but we know almost nothing about individual members. Most people do mention the eyes, though, when they meet the central members in person."

The yellow, snake-slit eyes. Right.

"So we're dealing with someone richer and even more 'pureblooded' than Malfoy. Great." Ron snorted. "He looks shifty."

"Ronald!"

"What? He does!"

Harry had no idea what to think, yet.

o.o.o.o.o

When it came to new arrivals to the school, Harry thought later that week, Dr. Oto was a million times more tolerable than Lockhart.

All Harry had done was spill some unfinished Pepper-Up on his lap (which was entirely Malfoy's fault, as he would tell anyone who asked), but it had left strong enough burns to get Harry sent to the Hospital Wing. He figured that, if nothing else, at least he'd get to meet the new healer.

"I could take care of it, Poppy. If you don't mind?"

"Go right ahead. I still need to see your spellwork in action."

Harry grudgingly took off his pants to expose the burnt skin when asked, and waited as patiently as he could as Dr. Oto started healing.

"So, why did you choose to come to Hogwarts? Why now?"

Dr. Oto didn't look up from where the skin was slowly changing to a more normal color. "I came here because, of all the places my family has ties to, this castle is the strongest bar two. I chose now because of what occurred last year."

He looked up with a smile as the burns finished healing. "We like to keep an eye on our projects."

Harry wasn't sure what to think of that. "How old are you?"

"Older than I look. Now, back to class with you. I'm sure you've still got some learning to do." Dr. Oto stood up and waved his wand at Harry's pants, vanishing the remaining stains. "Say hello to Nick for me, would you? He hasn't been by to see me, yet."

"Nick?" Harry said, as he pulled his pants on.

"Your house ghost, of course." Dr. Oto smiled at him, and Harry thought, for just a moment, that he could see a hint of blue in the man's white hair. "Off you get. Potions aren't going to brew themselves, you know."

Harry… Harry only wondered how Dr. Oto knew Nearly-Headless Nick.

o.o.o.o.o

Harry didn't see Dr. Oto more than peripherally again until Nick's Deathday party, when the man was one of the only other living people at the party. He was cheerily conversing with the Grey Lady and the Bloody Baron, and Harry didn't understand a word of it. Neither did Hermione.

"Well of course you wouldn't," the Fat Friar told them. "That form of English hasn't been understandable in centuries."

"What do you mean?" Harry asked.

"They're speaking English as it was spoken in the Founder's time. Hadn't you guessed?"

They hadn't.

(When they found Mrs. Norris, petrified in a hallway filled with water, Dr. Oto's face was lacking his customary smile, and his strange yellow eyes seemed more interested in the bathroom than the cat.)

o.o.o.o.o

"Does the concept of refraining from getting involved in branches of magic that you are eminently unqualified for somehow fail to present itself as a poor one?" Dr. Oto asked, glaring at Lockhart while Madam Pomfrey tutted over Harry's arm.

Lockhart appeared distinctly ruffled. Harry figured it was because of how the question was phrased; Harry certainly wasn't sure what Dr. Oto was saying.

"I assure you, I've used this spell on previous—"

"You are not a healer by any definition. In an emergency situation, I would accept a faulty attempt at healing, but this most certainly did not qualify." Dr. Oto's face was much less amused and pleasant than usual, Harry thought. The man's smiles usually seemed at least a little unnatural, but if this was the alternative…

"Get the hell out of my Hospital Wing." Dr. Oto almost snarled the words, and Harry thought, for just a moment, that he saw actual fear on Lockhart's face.

"It's my Hospital Wing, Mitsuki, and I'd remind you to watch your language around the students." Madam Pomfrey said sharply. "But I do agree with the sentiment. We have the situation covered, Professor Lockhart. Mr. Potter needs rest, and I doubt he will have the chance to enjoy it with you hovering. Any of you."

The final words were addressed to the Gryffindor team and professors that had come in as well, and everyone save for the Healers and Harry trooped out.

(Well, Hermione and Ron stayed a few extra minutes, but even they were shooed out by Madam Pomfrey quickly enough.)

o.o.o.o.o

When Colin Creevey was brought into the Hospital Wing, Harry did his best to stay still and quiet, watching the still body brought in by wandlight.

"Where?" Dr. Oto asked, his smile gone completely. His eyes are more visible than usual, Harry thought, because when the man smiled, you saw nothing of them. "Where was he found?"

Harry listened as they related how Colin was found on the staircase, watched as Dr. Oto and Madam Pomfrey cast every spell they could think of on the younger boy.

"I'm going to contact my parent and uncle," Dr. Oto told the other adults. "I may have solutions that are quicker than the Mandrakes, but they aren't formulated for quite this situation."

"You've encountered petrification before?"

"In several forms. This one is… familiar, but the condition is delicate." Harry couldn't see Dr. Oto's face, but there was something in his voice that certainly communicated displeasure. "Headmaster, if we could have a word in your office?"

"Is it a matter of secrecy?"

"…Well, no more than any other part of my history. Minerva and Severus are welcome to come, though I believe Poppy would prefer to stay and care for Mr. Creevey. Unless…?"

"You're not mistaken, Mitsuki. Go ahead, shoo. Leave an old woman to her work."

There wasn't much left for Harry to eavesdrop on after that.

o.o.o.o.o

So… things happened. A lot of things happened. Like Harry finding out what a "Parseltongue" was, and Justin getting Petrified, and getting accused of being the Heir of Slytherin. That was less than fun.

"Ridiculous." Dr. Oto said at one point, not speaking to Harry, but within earshot of him. "Slytherin's line never extended past a single generation. Any remaining heirs would have to be at least a millennium old."

Hermione was also there, as was Ron, and as per usual, the girl immediately pursued the opportunity for new knowledge with little regard for anything else. She waited for just long enough to sense a lull in Dr. Oto's conversation with Professor Flitwick, and then jumped in.

"How do you know that? It's not in any of the books I've read on the Founders, not even Hogwarts: A History."

"The ghosts," Dr. Oto answered, apparently not even the slightest bit bothered. "There are a handful that have been here since the school was founded; one of them was the daughter of a Founder herself."

Hermione seemed a little shocked by that. Harry remembered what Dr. Oto had said about Nearly Headless Nick, and wondered if the doctor (and that was Harry's main resistance to Ron calling the man worse than the Malfoys; he called himself a doctor, not a healer, and that was a thoroughly Muggle term) simply considered it normal to befriend ghosts and learn from them. Hermione certainly seemed to like the idea, once it was opened up to her.

"But there have been lines calling themselves the Heirs of Slytherin for generations," Hermione finally argued back. "Not many, of course, but—"

"Ah, yes, well…" Dr. Oto seemed to be suppressing a smile. "Not quite descendants of Slytherin's children. Creations, more like."

There was a very quiet pause at that.

"What."

"Salazar was a very avid tinkerer, when it came to biology. He was helpful in his own way, and pioneered artificial insemination and other fertility-related advancements long before anyone else bothered with them." Dr. Oto told them, apparently enjoying the chance to tell a bit of history. "He actually aided quite a few people with having children, but would often… augment the child in some way. Nothing intense or inhumane, and always with the parents' permission, but a few of those experimental results, while still wholly human, considered themselves his heirs in some way. Which, considering Slytherin did have heirs already, however little they bothered with continuing the family line, was rather presumptuous of them."

The shocked silence lasted a few seconds again, and then Ron leaned over to Harry and muttered, "Can we get him to teach History of Magic instead?"

Dr. Oto laughed.

"Mr. Weasley," Professor Flitwick scolded, "You shouldn't disrespect your professor like that. I understand that Professor Binns is not the most engaging of instructors, but he is a very old and distinguished member of our school."

"Ah, I do believe I have views on history that your school, and more importantly, your government and certain parents, would disapprove of." Dr. Oto hummed a little in thought. "In any case, I won't be staying here for longer than necessary, though how long that ends up being is thus far an indefinite period."

Harry wasn't sure if he felt this was a good thing or a bad one. Hermione, apparently, was far more interested in pursuing the original point. "The reason people think Harry is the heir is because of he can speak to snakes. The most well-known wizards recorded to have that ability were Slytherin and Voldemort, so—"

"Merlin had the ability as well, actually. He didn't broadcast it, but he certainly had it." Dr. Oto smiled as he said this, cutting Hermione off. "And Voldemort's ancestral line, the Gaunts, were a result of Slytherin's attempts to see how Parseltongue was transmitted from parent to child, and which alterations to genetic structure were key to causing it, if magic itself wasn't responsible."

"…Dr. Oto, I believe we would all appreciate it if you were a little less cavalier in delivering such information." Flitwick said, looking a little perturbed himself. "Are you certain you learned all this from the ghosts?"

"The Oto family does hold some of Slytherin's experimental records in our care," Dr. Oto confided, his eyes laughing with some hidden, quiet joke that nobody else understood. "But the Grey Lady could certainly tell you plenty of this information, if she thought it worth telling. She was Ravenclaw's only daughter, and while she was far more stubborn and willful than her mother, she was certainly more than intelligent to take interest in Salazar's doings."

"So just speaking Parseltongue wouldn't make anyone the heir of Slytherin." Hermione said, as though seeking clarification.

"My dear, if that were all it took, I could name a half-dozen people off the top of my head that could compete for the title." He paused a moment, thoughtful, and then leaned forward so that he could whisper without the rest of the hallway hearing. At least, that was what Harry expected, and what everyone else leaned in to hear.

Instead, with a small burst of hissing and quiet snarls, Dr. Oto spoke in a language only Harry understood.

"Myself included, of course."

Harry stood stock-still as the man stood straight again, a self-satisfied smirk on his lips.

Even Flitwick was gaping.

"I did say we had a number of Slytherin's records in our care. I never said we left them alone." Dr. Oto's smile was a languid one, seemingly relishing in their reactions. He leaned back against the railing, seeming like he was ready to topple right over it and into the chasm below. "Chin up; this really isn't even the most impressive of what I can do from genetic augmentation. I'm nowhere near as visibly changed as some of the people who raised me. Kabuto would make your purity-obsessed government froth at the mouth, with what he's done to himself in the name of science."

"So you're…"

"Still human. All the most distinct markers of species differentiation are missing, no matter what people may try to argue. I could procreate if I so chose, and my children would be able to do so as well, which is really the most important part of the definition." He smiled. "As for pureblooded or not… people do come to the strangest conclusions, don't they?"

He leaned back further, and Harry felt himself cry out as the man really did fall back and over the stone, rushing forward in a futile attempt to grab him before he crashed to the ground in a bloody mess. Screams from below indicated that others had noticed the man plummet past, but they didn't last nearly long enough for the corpse Harry expected.

When he (and Ron, and Hermione, and Professor Flitwick) reached the rail and looked over, it was to see Dr. Oto standing on the ground floor, some eighty feet below, waving up at them. Harry could just barely make out the man's smile before he turned and began walking away. Just before he left earshot, he called back over his shoulder, "I'll see you at dinner, Filius!"

Ron was the one to break the silence.

"What in the name of Merlin's saggy—"

"Ronald!"

o.o.o.o.o

"Are we sure he's not the heir of Slytherin?"

"He basically admitted to not being a pureblood, and… well, I don't think anyone claiming to be the heir of Slytherin would admit to being anything less than pureblood and… I don't want to say pure human, but unaugmented, perhaps."

"…So, we'll add him to the maybe list."

o.o.o.o.o

Dr. Oto stared at Hermione for all of three seconds when she entered the Hospital Wing, covered in fur and sporting a pair of fuzzy cat ears. He snorted something that sounded like "nekomimi," (which was definitely not Parseltongue, but Harry had no idea what it actually was) and immediately ushered her over to a bed.

"Oh, but I would love to get some data from this incident." He muttered. "Ms. Granger, if it's not too presumptuous to ask, would you mind if I took some samples?"

"Samples?" Hermione practically squeaked.

"Blood, hair, tissue… I can do it painlessly using magic, but you are well within your rights to refuse. Botched animal-hair Polyjuice aren't exactly common, and while these are far from perfect experimental conditions, any information helps in the goal for further refinement of future variations on the potion." Dr. Oto informed them, bustling around in search of… something.

"Polyjuice potion?" Hermione asked, sounding for all the world like she had no idea what he was talking about. "What's that?"

"Don't be coy; I can smell the remnants of it from here. I assume you spilled some on your robes?" Dr. Oto didn't even look at them when he levelled the accusation. "I'm impressed, though. Most people your age wouldn't be able to get even part of the potion correct, let alone the entire thing. You're a very skilled young woman."

Hermione didn't blush, or if she did, it was hidden behind the fur. Her ears did fold back a little though, laying just a little closer her head. "I'm sure I don't know what you mean."

"At least cats are fairly well-regarded. Imagine if you'd accidentally gotten hair from your friend's pet rat instead!" Dr. Oto told her brightly, finally coming back to the bed with a tray of potions. "Drink up, now."

He watched as Hermione choked down the potions, which Harry figured was standard practice since Madam Pomfrey tended to do the same thing, making sure people actually did as they were told and drank their medicine.

"You really shouldn't be messing around with things this far above your level without supervision," Dr. Oto said after a moment. "Experimentation is all well and good, but you really ought to make sure someone's there to catch the mistakes. You ended up with one of the most benign problems you could have, with this potion. Not everyone gets that lucky."

"Lucky," Hermione repeated, with almost a laugh. "You call this lucky."

"Considering the alternatives, absolutely." Dr. Oto muttered. "You haven't seen what a seriously imbalanced potion can do."

"Don't give the students nightmares, doctor." Madam Pomfrey said as she swept out of her office. "I've enough trouble keeping them in their beds at night."

"They're children, Poppy. They've every right to be a little excited." Dr. Oto swept to his feet and brought the vials over to the sink, where they abruptly vanished to be cleaned off… somewhere.

(House Elves, Harry later learned. They would be washed by House Elves.)

o.o.o.o.o

Valentine's Day was a disaster of epic proportions. Lockhart was evil, Harry was sure of it, if only a very petty kind of evil that you didn't normally pay attention to. An annoying evil.

Harry got more Valentines than he wanted, which wasn't very many, but it was still more than his ideal of "zero."

Dr. Oto, he noticed, got a good dozen or so, each of which he read perfunctorily and then set aside, returning to his conversation with Professor Sprout.

Disappointment abounded, but the only thing Harry really heard on the subject was that people were generally turned down with "I'm older than I look, and you are far too young for me as a result. Perhaps this classmate would be a better choice?" and then pointed in the direction of some unrequited crush they'd never noticed with unerring and unnerving accuracy.

Harry wondered why the hell Dr. Oto was paying that much attention to student romances, but saw him talking to a few of the ghosts with Valentines in hand and figured that was probably it.

It was always dead people with that man.

(When Harry found the diary, tucked it away and planned to see what was so special about it, he was too focused to notice the doctor's stare following him off to Gryffindor tower.)

o.o.o.o.o

"I need to speak with Aunt Karin, or my parent. It's about soul fragments, Uncle Juugo. Yes, the Riddle problem."

o.o.o.o.o

When Hermione and Penelope Clearwater got petrified, things took a turn for the worse in all sorts of ways. Harry figured the absolute worst was avoided by, well…

It went like this.

The Quidditch match was cancelled. The petrified girls were discovered. Everything was, more or less, looking terrible. Rumors were circling that Dumbledore was going to get sacked, or arrested, or any number of things, and Harry went to lunch feeling sick, sicker than he had in a while, which was saying something. He made plans with Ron to sneak out to see Hagrid and ask some questions, got a little distracted by the announcement of a curfew, and then got very distracted when the doors to the Great Hall slammed open.

Those doors were massive. Slamming them open was hard.

"Mitsuki!" A redheaded woman stood in the doorway, and she looked… angry, probably. Irritable, maybe? She didn't seem happy, but there was an air about her like "annoyed at the universe" was her natural state of being.

"Aunt Karin! You got my messa—"

The woman, who didn't really seem old enough to be an aunt to a man of Dr. Oto's age (but Harry ignored that, since he'd learned that wizards aged at different rates than muggles, and this could have just been an extreme case; the woman looked to be in her mid-thirties), cut him off with a stream of rapid, angry Japanese. At least, Harry thought it was Japanese. Dr. Oto had mentioned once, during a visit to the Hospital Wing, that it was his mother tongue.

"Ahem." Professor Dumbledore interrupted with a cough. "Might I ask your name?"

"…Karin Uzumaki. I'm Mitsuki's aunt. I'm here as the Oto family representative for investigations as to the recent situation at your school." Her voice was, when calm, low and mostly smooth, but what really shocked Harry was the heavy hints of an accent that would have been likelier seen in the Southern US. Refined, sure, but still. Very country. "I'm stonewalling your Board of Governors, by the way. I'll also need to speak with Mitsuki."

Mutters roamed the room, because nobody had forgotten the information that those who did their research had spread at the start of term. They all knew about the Oto family by now.

"Aunt Karin, when you say stonewalling…"

"They're terrified of me. Can't imagine why." The woman, Ms. Uzumaki, rolled her eyes and started walking towards the teachers' table. The students did not display much subtlety when they leaned away from her.

"Did you threaten them?"

"No. Threatened Suigetsu over the phone in hearing range of them, but he was being an ass." Ms. Uzumaki said, and then came to a stop right in front of Dumbledore, turning her attention fully on him instead. "Headmaster Dumbledore, if there's a chance we could speak in private? Or at least, more privacy than this. I wouldn't care about the professors sitting in."

It took a few seconds, but Dumbledore nodded, looking grave. Harry wasn't sure what was going on, but… the ghosts were watching, quiet and still, which infected the rest of the room with similar silence. The Ravenclaw House ghost, a beautiful woman with long, dark hair, floated forward to Ms. Uzumaki's side, whispering to her.

Harry had no idea what this woman did to command the respect of even Peeves and the Bloody Baron.

"She hasn't changed at all," came the whispered sigh from Nearly-Headless Nick, carrying easily in the near-total silence.

"You know her?" Harry whispered, and Nick nodded.

"Though the Grey Lady knows her best."

Harry… Harry didn't ask any more questions, too caught up in his own thoughts.

o.o.o.o.o

Harry was there when Malfoy tried to corner Ms. Uzumaki, talking up his father's role and power, and trying to… Harry wasn't actually sure what he was trying to do. Set up a meeting with Ms. Uzumaki and his father, maybe.

"Do I look like I give a shit?" She interrupted after two and a half sentences, stalling Malfoy out. It was an effective tactic, given that it made the Slytherin gape in shock for a second.

"E-excuse me?"

"I said, do I look like I give a shit? About your daddy, your blood status, anything." The redheaded woman leaned forward until she was eye-level with Malfoy. "Look me in the eye, and tell me: is this the face of someone gives a single flying fuck about what you have to say?"

Malfoy was once more relegated to staring in shock.

"Aunt Karin, the boy is thirteen. Let him live a little." Dr. Oto came up to Ms. Uzumaki's side and put a hand on her shoulder, guiding her back to standing fully straight. His accent had also started to shift to something more American, which Harry thought was weird, but… well, some people probably just picked up accents faster than others, right?

"He's an obnoxious brat." The woman muttered, but turned to Dr. Oto and produced a manila folder full of papers that Harry hadn't seen before. "Not a scroll, not tech, but here. You'll be interested to see what we found of—"

"Is this the result of the placental stem cell studies we were doing?" Dr. Oto asked as he took the file and flipped it open. "That's… the blinded Chinese Fireball. I thought we'd written her off as a lost cause?"

"Sasuke decided to try again. You know how he gets about eyes. But look at the changes to the degeneration patter in the optic nerve." The woman took a step closer, now completely ignoring all the students around her, Malfoy and Harry included, and pointing at something on the papers.

Harry wondered, in the back of his mind, why he thought it was so funny that she'd brought a manila folder and printed paper instead of a scroll or parchment. It just looked so utterly muggle, and in the middle of Hogwarts, that was…

"Weird," Ron muttered. "Mate, do you have any idea what they're—"

"No."

"Bugger."

o.o.o.o.o

The spiders were a bad idea.

Hagrid's arrest may have been delayed and brought up closer to the castle for Ms. Uzumaki to argue the issue, along with Dumbledore's sacking, but Harry and Ron still followed the spiders.

It was such a bad idea.

"You boys are in so much trouble." Dr. Oto's now-familiar voice greeted them when the Ford Anglia finally dumped them outside of the forest. The amusement in his tone matched that on his face, when Harry looked up, even if the moonlight didn't give him much to work with. "Come on, up you get. I'll be the one setting your detentions."

Harry wanted to collapse back on the grass and groan, but got up and trudged back to the castle instead. Ron followed him.

o.o.o.o.o

"He'll be useless." Harry commented as they pushed Lockhart into Moaning Myrtle's bathroom. "Literally any other teacher would be more useful. Even Filch would be more useful, and he hates kids enough that I'm half-convinced he'd offer us up as snacks to the Basilisk instead of doing anything to help."

"He's the best we've got, though. Only one we can bully into helping us save Ginny." Ron's voice was stubborn, angry. Harry didn't know what having a sister would be like, but he thought he could maybe imagine what Ron was feeling. Maybe if he compared it to how he'd feel if someone kidnapped Hermione?

"Alternatively, you could try to convince someone who actually has experience in these matters to help."

At this point, Harry wasn't sure why he was letting himself be surprised anymore. Dr. Oto kept showing up.

"What do you mean, experience in these matters?" Lockhart asked, looking suspicious. This had the odd effect of making Ron, who had also looked suspicious, suddenly get very conflicted as he instinctively wanted to disagree with Lockhart, but didn't want to stop being suspicious of "the creepy doctor that talks to snakes."

"I mean, you are planning to find a giant snake. One which, might I remind you, none of you have any experience subduing." The doctor strode forward. "Moreover, the two of you are still schoolchildren, while Gilderoy's specialties lie in mental magics, not anything to do with large creatures."

"And you?" Ron challenged, ignoring the stiffening at his side of Lockhart himself.

A peculiar glint entered Dr. Oto's eyes. "I've spent a lot of time with magical creatures. Uncle Juugo is quite fond of them."

"Which ones?"

"All of them." Dr. Oto smiled. "Now, Mr. Potter, I believe I heard you were planning on opening up the Chamber of Secrets?"

Harry gulped and turned towards the sinks.

o.o.o.o.o

"Oh, now aren't you just gorgeous" Dr. Oto practically cooed as the Basilisk came slithering out of the statue. Harry figured that even if Lockhart and Ron couldn't understand the man, there was something obvious in his tone and attitude. "What's that soul fragment been doing to you? If you wanted a meal, all you had to do was ask. I'd have found you a nice cow, or perhaps a pig? I'm sure the House Elves could have rustled up something nice and meaty for you."

The Basilisk had seemed intimidating at first, especially with how quickly Harry had snapped his eyes shut, and he figured the others had done the same. Now, though…

"How… how are you not dead of its gaze?" Riddle sounded offended.

"Her. Her gaze. As for your question… my family has been pushing the limits of science and the human body for longer than this country has existed." Dr. Oto seemed… cold. Harry couldn't see his face, but he'd never heard the man sound so condescending. "We've tied ourselves to snakes, and them to us, for the same amount of time. When it comes to this…"

He switched to Parseltongue, fake cheer ringing through his words as he sing-songed, "Anything you can do, I can do better!"

The rest of the night proceeded similarly.

o.o.o.o.o

"You dumbasses."

This was how Ms. Uzumaki greeted them as Fawkes flew them out of the pipe. She didn't seem surprised or offended, just swept forward to check on Ginny like she didn't trust Dr. Oto's judgement. Nobody else was waiting for them.

"Ah, but I'm your dumbass, Aunt Karin."

"The rest of them aren't. I'm not taking responsibility for this many children. Helping out with you was more than enough." The woman shot back. "You, girl. Ginny, right? What can you tell me about what happened to you?"

Ginny tried to answer, and instead burst into tears.

"You broke her."

"Shut up, brat."

"She's crying, Aunt Karin. I almost forgot how bad you are with stranger's kids. H—"

"If you don't shut the fuck up, I'm going to rip off your arms and shove them up your ass, you little prick."

Harry choked on thin air. Literally no one else had any idea what Ms. Uzumaki had said when she whirled around to hiss at Dr. Oto in Parseltongue, but Harry knew. He didn't want to, but he knew.

"Mate, you okay?"

"Yeah, I just… she said something weird."

"Tch." Ms. Uzumaki scoffed, and then turned back to Ginny, who hadn't stopped crying yet. Harry was concerned. He did not know how to handle crying girls. He didn't know how to handle a crying anybody. "Ronald, right? Get over here and comfort your sister."

Ron looked about as confident in his ability to comfort Ginny as Harry would have, but trudged over and hugged his sister from behind, glaring at Ms. Uzumaki once he did.

"Okay. Sorry kid, it's been a while since I treated someone who wasn't… anyway." Ms. Uzumaki made a quiet huffing noise. "I'm going to have to ask you some questions, and I'd like for you to answer them as best you can. Don't worry if you can't answer right now, or at all. We can follow up later if we have to."

"We could also do this somewhere that isn't a bathroom." Dr. Oto pointed out. "I'm fairly certain one of the teachers could loan their office."

Fawkes made a trilling noise and lifted into the air from his perch on a wall light.

Dr. Oto and Ms. Uzumaki exchanged a look.

"I never learned to speak bird."

"No shit." Ms. Uzumaki got up and dusted off the knee-high socks that she was wearing under her ruffled skirt. "Lead the way, then. And, ah, Ginny? If you're still feeling ill, I could carry you."

"I can walk."

o.o.o.o.o

Harry could feel the disapproving stares being levelled on everyone in the room as they trooped in. He could feel those stares diminish as the Weasley parents immediately started hugging Ginny, but they didn't disappear. Funnily, he got the feeling they were mostly aimed at the adults.

"I'll explain," Dr. Oto offered, and proceeded to recount the entirety of their adventure. He didn't skimp on details, and Harry winced more than once during the telling.

Ron added at the end that he still didn't know why Fawkes had shown up.

"The castle sent him." Dr. Oto said as he stroked the phoenix's back. "She knew we'd need a way out, so she sent the one who could hear her calls."

"Is that why… she came to find you as well?" Mrs. Weasley asked, gesturing at Ms. Uzumaki, with the awkward air of a person who had forgotten the name of someone they'd only recently been introduced to.

"No," the woman in question answered curtly. "I sensed my nephew going below ground with several other people and concluded there would be a need for medical attention. Clearly, I wasn't wrong."

"I could have handled it myself."

"Bullshit."

"Language, Auntie."

Harry suddenly realized that he found himself torn between hating and respecting these people.

So very, very torn.

o.o.o.o.o

"Uzumaki." Lucius Malfoy said as Harry left Dumbledore's office, voice filled with something that could have been loathing if it weren't so polite. "I wasn't expecting you to still be here."

"It looks like we're going to be checking in a bit more on the school in the future. The head of the family can't bear to see a good investment go to waste." Ms. Uzumaki drawled, leaning against a wall. Dr. Oto was right behind her, smiling away politely. "With everything that's happened this year and the last, it seems things are going to be getting… exciting."

Mr. Malfoy's lips twitched downward almost imperceptibly. "I see."

"Hmph." Ms. Uzumaki pushed away from the wall and headed towards the railing that opened onto the empty body of the castle. "Word of advice, maybe teach your son a bit more about persuasion tactics that don't rely on name-dropping or negging."

The woman punctuated that statement by stepping onto the railing and jumping over it, a motion that Dr. Oto quickly followed. Harry didn't bother rushing to see if they'd survived; he'd learned his lesson last time. On the other hand, Mr. Malfoy did go to see, probably out of morbid curiosity. This was the point at which Harry noticed Dobby.

And well… there was really only one way for events to play out, after that.

o.o.o.o.o

"We're back," Karin called as she opened the millennia-old doors that lead to the central building of New Otogakure. "And boy, have we got news."

The only person in the entry hall was Kabuto, who was reading a magically-imported newspaper. "Unless it involves the protective Fuuinjutsu around the Elemental Nations breaking down and rendering the Hidden Continent no longer hidden, I doubt I care."

"You were right, though." Mitsuki said, tossing himself down on the couch and dropping the internally enlarged bag he'd used to bring his things on the ground. "Voldemort is stirring up trouble again, and on exactly the schedule you predicted."

"That wasn't exactly difficult," Kabuto countered. "He's a very predictable person."

"Still calling himself the heir of Slytherin, too." Karin snorted, yanking off her boots and stretching. "God, I hate long-distance portkeys. Give me a Hiraishin seal any day."

"You invented portkeys," Suigetsu called from the hallway as he made his way in. "You don't get to complain about how uncomfortable they are."

"Fuck you and the horse you rode in on." Karin didn't even bat an eyelid. "And seriously, how long have we been working on countering the rumor that Slytherin even had heirs other than, well…"

"I think we gave up around seven centuries ago, when Sasuke decided infusing random objects with his Rinnegan powers was a good idea for some reason." Suigetsu grinned.

"That," Sasuke said, appearing in the doorway, "was me fiddling. You were the one that pretended to be Death and handed them over to group of random wizards."

"They wrote fables about that day." Suigetsu's grin only widened. "Children's tales! How awesome is that?"

Karin kicked him off the couch. Suigetsu squawked.

"You're almost two and a half thousand years old," Juugo said as he entered the room, drying off his hands with a dish towel. "And yet you still act like children."

"Thank you for being the voice of reason." Kabuto muttered, shifting over enough to make room for Juugo. "Any other news?"

"The Malfoys are still prats?" Karin offered, sagging until her head lolled over the back of the couch, and she stared at the ceiling. "The elder one is afraid of me, which is hilarious. And Helena's just as lovely as ever."

"Don't fuck the ghost, Karin." Suigetsu teased.

"Please, like you never tried." She didn't even move her head.

"I… shut up."

"That's enough, children." Orochimaru swept into the room, taking his own seat in a cushy armchair. "I'm guessing you have news?"

"Yeah, the latest generation of your experiments from the tenth century is a giant piece of trash." Karin told him. "But you already knew that."

Orochimaru did not pinch the bridge of his nose or sigh, but he did turn to look at Mitsuki instead. "Anything?"

"They still respect us." Mitsuki shrugged. "Mostly because of the money, but there's respect for the history, too. None save for the ghosts have figured out we're immortal, but…"

"Only a matter of time, with image-capture technology marching on as it has." Orochimaru sighed. "Well, we were never planning on keeping it a secret forever. We'd have been much more careful with portraits and the like if that were our goal."

"To be fair, whoever you asked to make the statue in the Chamber took an absolutely ridiculous amount of artistic license." Mitsuki pointed out.

"That was Godric's doing, actually."

"…I'm not nearly as surprised as I should be."

"Do you think they'd start figuring it all out if you showed up?" Suigetsu asked, lounging lengthwise on the couch he'd claimed. "Like, you don't put a lot of effort into hiding it."

"I'm sure a rumor would start eventually." Orochimaru allowed. "Though I would personally prefer waiting."

"For the appropriate dramatic moment, as per usual." Sasuke sighed. "Just like a Sannin, really. With what little I learned of Jiraiya, and with what I know of Tsunade from her… visits—"

"She's the only other person from our time left, Sasuke. The only one older than Orochimaru-sama, too. Show a little respect." Kabuto reprimanded.

"Says the man who once tried to kill her."

"I was aiming for the apprentice, actually."

"Enough," Orochimaru cut them off. "But yes, there will be an appropriate time to reveal that Salazar Slytherin was simply a pseudonym I used while aiding in the construction of the school. That time is not yet at hand. These people have twisted the words and teachings I left behind, even those who should know better, and we will remind them that I never actually advocated purity or any such nonsense eventually. For now, we will meddle more indirectly."

Mitsuki smiled. "Oh, this is going to be fun."

o.o.o.o.o

A/N: So, uh… Naruto universe plotline happened about 2400+ years before the Harry Potter timeline. Oto fam survived because Orochimaru's has magic science, and Tsunade survived because… Tsunade.

There's going to be more information at a later point about what the hell happened to the Elemental Nations (and why their tech was time-shifted over 24 centuries out of phase with everyone else), what Oto fam was doing before and after they meddled with Hogwarts, what Orochimaru's actual goals/teachings/relationships at that time were like, what the current dynamics of the Oto fam are like, and so on. You can probably assume that the epilogue didn't happen as in canon, other than Mitsuki existing, and Orochimaru getting distracted by becoming a really supportive suburban parent and dragging Team Taka into his projects.

Orochimaru is definitely nonbinary, by the way. He still uses he/him pronouns because of habit, since they don't case him dysphoria, but he's nonetheless canon nb, so he's nb here too.

I'm going to keep writing this snapshot-style. If I think something is either too similar to canon to bother with, or is something that the reader can pick up on with a minimum of critical thinking, I'll gloss over it. I'll also gloss over things that are somewhat spoiler-y (like Merlin).