Is the Heir of Slytherin supposed to appear in the middle of their diagram? Because here someone is!

"...didn't anyone ever tell you not to draw on the floor?"

"What--who are you?"

"Blimey, Hermione, you said we'd get images of other parts of the castle, not some bloke with wings!"

"...uh, hello, my name is Cam and I'm the demon you summoned and if that isn't what you were going for you have been failed by your educators."

"Demons exist? Why does nobody ever tell me these things?!"

"Hey, I didn't know that one either."

"What are demons, exactly? Because you don't look like the ones in muggle stories and I haven't read anything about demons in wizarding books. Not that sounded reliable, anyway."

"Muggle stories?"

"The stories muggles tell about demons? Where they have bright red skin and pitchforks and offer you knowledge in exchange for your soul?"

"Wait, maybe he's a muggle demon. He doesn't have a wand. You don't have a wand, do you?"

"I can't say that I do. Or a pitchfork. And I don't think I'd look good in bright red and I don't want your souls."

"Good, I don't have one going spare."

"If we brought a muggle into Hogwarts we're going to be in so much trouble. But if you're not magic, how do you have wings?"

"...because I am magic, actually? I'm a demon! Where am I, please?"

"Hogwarts School of Witchcraft and Wizardry. It's in Scotland; if you were British I'd say you would have heard of it if you were magic but you sound American so I'm not sure."

"I could switch dialects but as long as this one's intelligible it's my default. Is there perhaps some sort of adult you might reasonably inform about, uh, this?"

"I suppose we should tell Professor Dumbledore. Or Professor McGonagall. Or Professor Lockhart."

"Why? They weren't any help last year, and that was when they knew what was going on." 

"If we have to tell someone it should at least be McGonagall. Lockhart's useless."

Cam has not met any of their professors. He does wonder why people who teach what look like prepubescent children style themselves "professor". "There's not a terrific rush about it if this isn't the best time."

"Maybe you could explain what a demon is first." Maybe they can solve this without telling anyone in authority why they were doing unfamiliar rituals in a girls' bathroom.

"We're the kind of daeva that makes stuff. Do you not know about angels and fairies either?"

"Fairies are a sort of magical insect, but I've never heard them called daeva or compared to demons and angels. What sort of stuff do you make?"

"Arbitrary material objects," he says, processing this assertion. "Hey, does there happen to be any magic you can do as a demo, I'd like to see."

"Can you make a picture of the Heir of Slytherin?"

"Ooh, yes, that," says the girl, pulling a fancily carved stick out of her pocket. "And for a demonstration--wingardium leviosa!" She gestures with the stick, and the antique-looking tome lying open beside her lifts gently into the air. She guides it up to shoulder height, then grabs it and tucks it under her arm. 

"If 'being the Heir of Slytherin' is a conjurable parameter and the circle doesn't have a binding in it, which it probably doesn't, then maybe? Who's Slytherin?"

"Salazar Slytherin was one of the four Founders of Hogwarts. Someone claiming to be his Heir is petrifying muggleborns, possibly with magic he left hidden somewhere."

"If they might only be claiming to be his heir then it's less likely I can accurately conjure them, I might get an actual descendant who innocently operates a tea shop or something while their identity is used by another party. Uh, can you describe in detail more about the petrifying, thing..."

"It's been two students, a cat, and a ghost so far. They turn up unconscious, all stiff, like statues. Except the ghost, he turned grey and they had to blow him around with a fan. The teachers say there's a potion that might cure them, but it'll take all year to brew. And . . . right before the first attack, I heard a voice nearby, talking about how it wanted to kill, but I didn't see what was talking."

"Name one of the students for me? Or the cat, I suppose."

"Creevey. Colin Creevey."

Little diorama of Colin Creevy at the time of his petrifaction?

Kid holding a camera up to his face. Patch of floor and walls. Giant menacing snake head way bigger than the kid!

"...you said he was petrified, not, uh, vanished without a trace into this here very obvious-looking giant snake?"

"Bloody hell. . . . Of course Slytherin's monster would be an enormous snake."

"Harry, this explains why you were the only one who heard the voice, it's because you're a parselmouth! But I've never heard of a snake that petrified people--I need to go to the library--" she looks back and forth between Cam and the door, torn between two information sources.

"...do you also have a guess why nobody has seen the snake, because whatever a Parselmouth is I don't think I am one and I can see this, but maybe I have failed to conjure its invisibility gland, how should I know..."

"Well, all the attacks have been on people who were alone, but if it's not invisible whoever's controlling it would have to have a really comprehensive knowledge of the castle to get it around without passing anyone. Can I get a copy of Magickal Serpentes of the Known World?"

"I want to know where it is now," says the redheaded kid.

Magickal Serpentes in the left hand. Snek and environs in the right hand.

The girl grabs the book and grins like Christmas just got rescheduled to every Tuesday.

In the other hand: he gets the whole snek this time, and wow has it got some fangs on it. Also neon yellow eyes. The environs looks for a moment like it might be a big metal pipe that intersects itself at several points, like a nineties video game with bad hitbox programming, then the fact that metal pipe walls aren't meant to occupy the same place simultaneously makes it fall to bits.

"...well, that's... interesting," says Cam, looking at the bits of pipe. "Do you have any... Klein plumbing... around? It interpolated itself!"

"The Hogwarts hallways don't always make sense. You can go down a lot of flat corridors and wind up a floor higher. I guess the plumbing is the same way. And if it's in the pipes, that would explain why nobody's seen it."

"How the blazes is it meant to have entered the plumbing? It's huge! Even if Colin's a kindergartener it's huge!"

"Colin's a first year, he's eleven. And it's supposed to have been hiding somewhere called the Chamber Of Secrets, maybe it's got a way to get something big in the pipes?"

"The insides of the Hogwarts pipes expand to accommodate anything trying to move through them, so they can't get blocked. I read about it in Hogwarts, a History."

"I suppose that's one way to avoid needing to do competent non-Klein civil engineering. Side question. Why is it called 'Hogwarts'. You're speaking English, it can't have escaped you."

"Yeah, why is it called that?"

"I dunno, when you've heard it enough times it just sounds like a word."

"It's named after the town that used to be here before it merged with Hogsmeade, but the book didn't say where that came from."

"I suppose there wasn't realistically going to be a better answer than that to hand. So, it's a giant pipe-going snake, is that something you call wizard animal control about...?"

"Well, it depends what it's doing, doesn't it, if it was just a big snake then the Department for the Regulation and Control of Magical Creatures would have no problem, but it can't just be that . . . Oh no."

"Are they unable to regulate and control magical creatures that are... what, too magical?"

"No, they can handle most things with enough wizards, but look at this." She holds out the book, open to a passage on basilisks.

Of the many fearsome beasts and monsters that roam our land, there is none more curious or more deadly than the Basilisk, known also as the King of Serpents. This snake, which may reach gigantic size, and live many hundreds of years, is born from a chicken's egg, hatched beneath a toad. Its methods of killing are most wondrous, for aside from its deadly and venomous fangs, the Basilisk has a murderous stare, and all who are fixed with the beam of its eye shall suffer instant death. Spiders flee before the Basilisk, for it is their mortal enemy, and the Basilisk flees only from the crowing of the rooster, which is fatal to it.

"Someone's been killing Hagrid's roosters."

"...well, unfortunately, I can make roosters but they come out too stupid to crow. Will recordings do?"

"Electricity doesn't work at Hogwarts, but a phonograph might if it doesn't need a real rooster . . . Wait, are you thinking of taking on this thing yourself?"

"I mean, it seems probably a good idea to go grab your favorite teacher, but if Magic Animal Control can't do anything then something will still need doing, right? Are your teachers better at magic animal control than the professionals?"

"Dumbledore definitely is, but I still think telling anyone about you is a bad idea. Muggles aren't allowed in Hogwarts and they would probably decide you count as one."

"...and then what?"

"Dunno, but it's nothing good. We all get expelled?"

"I'm sure they'll be more concerned with stopping the Basilisk before anyone else is attacked."

"I mean, it wouldn't be that unreasonable for summoning like this to be an expulsion offense but 'that demon is not magical enough' would be a weird justification for that."

"Yes, we also might get expelled for trying a ritual out of a book that didn't do what we thought it did."

"There you go. Say, what year is it?"

"Nineteen ninety-two."

"I see, I see, thank you. What the hell."

"What year were you expecting?"

"Well, if I were expecting it very much anymore I wouldn't have bothered to ask, now, would I. 2179."

"Wicked."

"Wait, you've gone back in time? That's supposed to be really dangerous!"

"No one offered me an informative pamphlet before I accepted the summon!"

"I'm not saying you did it on purpose, but you should still be careful! If you're from that far ahead I guess you don't need to worry about running into your past self, but don't try to do anything that contradicts what you remember."

"Oh, no, if this is my 1992 I'm off being five years old somewhere. But I don't think it is, I'm pretty sure mine doesn't have wizards."

"Blimey, you're old."

"Harry, I really think we have to tell a professor. We'll need help finding the basilisk and killing it, and--Cam, if if you're from another world or something, like in the Chronicles of Narnia, do you know how to get home?"

"Whichever one of you summoned me can dismiss me, but supposing this is in fact a Narnia-type situation I'd rather stay and eradicate malaria and so on first."

"We appreciate it. Alright, Hermione, we can talk to McGonagall, but if she doesn't believe us this time either we should deal with it ourselves again."

"I think I'm fairly believable on inspection, I don't have an invisibility gland."

"I hope so." He starts for the door.

"Harry, wait. We should look around corners with a mirror first. That way if we run into the basilisk before we find McGonagall, at least we'll only be petrified and not--worse." She turns to one of the mirrors above the sink and starts trying to take it off the wall.

"- I think you can probably improve on the Perseus trick but I don't know the parameters. Colin had a camera? Harry can hear it talking? - What does it say?"

"Colin had a camera, Justin--Justin saw it through Nearly Headless Nick, Mrs. Norris saw its reflection so we know that works. And when I heard it . . . it said it wanted to kill."

"Charming. Mirrored sunglasses and also looking 'round corners?"

"Alright."

The others nod seriously.

Cam issues everyone including himself shades and a hand mirror. "I'm indestructible but that's not been tested against basilisks."

They all put their shades on; now they look like tiny secret agents in robes. "Indestructible? Wicked."

The outside of the bathroom looks to Cam's eyes like it's as dilapidated as the inside. Leaning walls, floors with gaps in them, stairs that look like they'll collapse if you look at them funny, let alone try to climb them.

"Is this some kind of illusion magic?"

"Oh, that's right, muggles see the castle as a ruin--we definitely need to find you a teacher, they'll be able to counter it for you. Just follow us for now."

"That would be dicey if I were afraid of heights but fortunately I am not. Why does it look like a ruin in particular?" Follow follow.

"Something people won't want to investigate as much as a castle, I think."

"What exactly did you mean by 'indestructible'?"

"I can get papercuts. If you attack me with a sword, it'll look sorta like I got a papercut. And either way it'll take a second or two to heal unless for some reason I want a papercut. Extrapolates as you'd expect given that."

"That's amazing."

"Well, hello children! And who is this?"

Very quiet "augghh".

"...uh, hello, I'm Cam, and you?"

"Why, don't you know? I'm Gilderoy Lockhart! Order of Merlin, Third Class, banisher of the Bandon Banshee, and five times winner of Witch Weekly's Most Charming Smile Award. Also Hogwarts Defense Against the Dark Arts Professor. Excellent wings, by the way, very imposing."

"Thanks, I made them myself."

"Professor, could you get him one of the charms that let Muggles see Hogwarts?" 

"Certainly, Miss Granger, anything for my most attentive student. Right this way." He sweeps off with a swirl of robes that's a bit too dramatic to not look rehearsed.

Okay, they're following this guy then. It remains a really good thing Cam's not afraid of heights. "This requires going somewhere? Do you not have your wand on you or do some things require extra doodads?"

"It's a necklace. A lot of persistent magic is enchanted objects; it's less likely to come undone that way."

"You should be glad it's a necklace," Harry mutters too low for Lockhart to notice. "Last time he cast a spell on me he got it wrong and I spent the night in the hospital wing."

"Huh. And there's just one around? Who-all comes to visit under typical circumstances?"

"I think all the teachers have a couple? It's mostly people's muggle parents."

"How considerate of them to have this, uh, disability accommodation on hand."

"Guess so, yeah. I haven't really thought about it, all my family are magic."

"I would be interested in pie charts of the demographics here but it is not urgent."

"You make charts out of pie?"

"It's a figure of speech, the charts are circles with wedges of different colors."

"That makes more sense but it's not as much fun."

And here's Lockhart's office! Lockhart presents Cam with a wooden disk on a leather cord and a long-winded story about how he once had to enchant one of these on the fly while rescuing the princess of some country Cam has never heard of.

"Is that some kind of secret magic country," Cam says, donning the necklace, "or the magic name for a country Muggles know by another name...?"

"I believe it's in the area muggles call Timbuktu. What brings you to Hogwarts, by the way? Would you like an autograph?"

When Cam puts the necklace on, the architecture goes from "crap even before the decades of neglect" to "beautiful and very well-maintained stonework". All the walls and doors are in the same places, at least.

"I don't really collect autographs, thanks. I was summoned."

"Professor, we know what Slytherin's Monster is. It's a basilisk."

"A basilisk? Fascinating. Unfortunately I have just been, ah, called away to, ah, a very important conference. I'm sure you'll all be able to handle yourselves without me." He pulls out a suitcase and starts tossing random objects into it.

...Cam looks at the kids because he does not know if this is expected wizard faculty behavior.

Yeah, this is pretty unsurprising.

No, this is very surprising!

"But you're the Defense Against the Dark Arts teacher! You can't just leave when there's a monster attacking the school!"

"Are giant snakes a dark art?"

"The Defense curriculum is supposed to cover protecting yourself from dangerous creatures."

"That's not the point, the point is that Lockhart's a fraud."

"Hmm. I can't have you lot going around spreading this story," says Lockhart, closing his suitcase and drawing his wand. "Totally incongruous with my image. So just to be sure . . . obliviate!" He flicks the wand at Ron.

"Eh? What's going on?"

That wand is going to be encased in a block of ice now, grown so as to break his grip but probably not any fingers! "What the actual fuck did you just do?"

"That was a memory charm. Ron, what's the last thing you remember?"

"Uh, we just found out there was a basilisk? Why are we in Lockhart's office?"

"Aaaaaaa! Wandless magic?!"

"You're lucky I didn't just snap it! Memory charm? I should snap it - do those wear off, are they reversible -"

"They might be reversible? Oh, Ron, I'm sorry, this is all my fault for trusting him."

Lockhart tries to break the ice off his hand by banging it on a table, winces in pain, and then stands there looking stymied.

Cam courteously melts the ice from his hand for him so the block with the wand in it rests on the table. "Do you have a... better... teacher somewhere we could try?"

"Professor McGonagall has never actually made things worse?"

"That sounds like a step up! I do not want to let this creep out of my sight right at this moment and mirrors or no mirrors the snake is certainly big enough to eat you guys up in one bite so I should be along for better-teacher-fetching too, so I guess he's coming with us. Are memory charms illegal, can he just be turned in or something?"

"I think it's illegal to use on wizards? It's got to be some kind of forbidden to use it on your student. Let's bring him to McGonagall, she'll know for sure."

"All right. Come along, Professor. Lead the way, kids. Ron, I apologize but I do not have a recording of the missing time. It was fairly uneventful though."

"Cam couldn't see Hogwarts because of the anti-muggle spells, so we went looking for a teacher to take them off and ran into Lockhart. Hermione told Lockhart about the basilisk, so he tried to run away and wipe our memories so we wouldn't know he had."

"Alright. Thanks, mate."

Ron and the others set off for, presumably, McGonagall's office.

Wibble. Lockhart follows, clutching his useless icy wand.

"I think maybe you want to put that down because I don't know under what conditions you could cast with it and if it looks like it might be occurring to you to aim it anywhere I'm just gonna wreck it. It's hard to overstate how offensive memory charms are. I will give you a pair of glasses like theirs though." Glasses.

Lockhart maybe did not expect or want glasses spontaneously appearing on his face, but he sure does have them! He jumps. He does also put his wand in his pocket, though.

"Your options are you have that on your person and I'm on a heck of a hair trigger about splintering it into a hundred pieces if you twitch, or I carry it and I am not," Cam tells him. "The glasses are an attempt at an anti-basilisk defense."

He'll hand it over and look extremely annoyed about it.

"Who are you, anyway? I've never heard of you."

"My name is Cam and you wouldn't have. Off we go."

Off they go! More beautiful stone hallways that connect at weird angles, and doors that the kids open by poking them. There are portraits on the walls; some of them wave and one says "Good morning!".

"Good morning," says Cam blandly, and, "are they people?"

"I don't think so? They're more like echoes, or recordings--they don't learn, they can talk about the lives of the people they're based on but not what they did last year, that sort of thing." 

"...okay."

They make one last 270-degree left and Hermione knocks on an elegant wooden door. It's answered by an elderly, stern-faced woman in green robes, who says in a crisp Scottish accent, "Well, this is quite the group. What brings you all here?"

"The monster is a basilisk in the plumbing and also this clown memory-charmed Ron. Hi, I'm Cam."

"A basilisk? Are you certain? How did you come by this information?" She spares Lockhart a "what is wrong with you" glare, but he's clearly not the most pressing concern right now.

"...magic? It's a long story. I can't personally distinguish basilisks from any other sort of inappropriately large snake but it looks like this." He hands her a plastic basilisk. "To scale."

"Wandless conjuration? Without a complete visualization of the object? I find that rather hard to believe." She looks at the kids, then back at Cam. "Can you replicate the third piece of parchment from the top of the central stack on my desk?"

Cam sighs and hands her that too.

It's a subscription renewal form for a transfiguration journal. Her eyes go wide when she takes it. 

"Well. This is unprecedented. I have a lot of questions for you but first I must deal with the danger." Evacuating the school or sending everyone to their common rooms might tip off the Heir, and if they decided to go out in a blaze of glory the consequences could be disastrous, so, "Do you know who is controlling the monster?"

"No, I'm not confident it's a conjurable parameter but if you want a lot of little plastic basilisks we can pan through its history and see if it's been meeting anybody?"

"Unless any of you know where the Chamber of Secrets is, I don't immediately see a better idea. Come into my office." She steps aside to let them into a room balanced on the knife edge between "office of an extremely organized person" and "office of a person with too many jobs".

In they go. "Is he dangerous at all while I have his wand, I'm new to all this wand-related stuff," Cam asks, gesturing at Lockhart. "I can try for the Chamber but the plumbing doesn't obey conventional geometry so I might just wind up with a lot of self-interpolating Chamber parts."

"It's certainly worth the attempt. And if your magic works by proximity, you could try everyone who was near the basilisk at the time of the last attack." She gives a time and date.

"I did a model of Colin Creevy - I believe it's still where I originally made it, didn't want to carry it around - and there wasn't anyone else present, but I can pan back from that." Basilisk surroundings at that time and date.

He gets a number of unaccompanied plastic basilisks, which McGonagall vanishes as they accumulate, and eventually gets one being addressed by a redheaded girl with her hands positioned as though clutching something that didn't come through.

"Ginny?! No way she's the Heir! She's not!"

"I don't know what wizarding terrorism demographics look like but I wouldn't have guessed a little girl," acknowledges Cam.

"Yeah, I'm with Ron, his sister really didn't seem the type. And your whole family's in Gryffindor; shouldn't the Heir of Slytherin be a Slytherin?"

"Well, the legend is just that it's one of his descendants, but whoever it is has been attacking muggleborns, and I don't see why Ginny would do that."

"Nonetheless, mister Weasley, if she has been near the basilisk and survived she might know more than we do about the matter."

"If wizards do primogeniture it probably can't be a younger sister. Is she findable by conventional methods or do you need me for that?"

"She's probably in the Gryffindor common room at this hour. Miss Granger, will you go and fetch her while I sort out the matter of alleged memory charms?"

"Alright." Hermione sets off.

"Uh," says Cam, "basilisk, roaming the pipes? Is sending her off by herself wise?"

"It's no more dangerous than it was yesterday, but yes, perhaps we should stick together." She calls Hermione back in and examines the group. "Any further objections before we go find Miss Weasley?"

"I, ah, I must protest against these ridiculous accu--"

"Objections from people other than you."

Cam has no objections. He offers McGonagall a pair of shades.

"Thank you." She transfigures the shades to match her prescription and swaps out her spectacles.

McGonagall in mirror shades looks extremely weird, but nobody is going to point this out. They set off, McGonagall contriving to both take the lead and not let Lockhart out of her sight.

Cam brings up the rear and conjures around corners.

There's nothing around the corners except, on two occasions, cats.

"I don't understand your abilities," remarks McGonagall. "You're not an ordinary wizard, or a muggle, or any sort of magical creature known to wizardkind. Where did you come from, what can you do, what are your limitations?"

"My species is in English called demons. From Hell. I can make arbitrary nonmagical material objects."

"And this 'hell' contains what, exactly?" she asks suspiciously.

"It started out containing literally nothing and now it has whatever we put there. It's a perfectly nice place, if a little too often radioactive for humans to be comfortable."

"And you have no designs on human souls?" she asks, with the gaze of a woman who can hear ten students say their cat ate their homework and pick out the two whose cats really did.

"None at all."

"Good." The "you better not" remains unspoken. "And exactly how arbitrary is arbitrary objects, besides not being able to make enchanted items?"

"No antimatter, nothing including vacuum unless I start it in a vacuum, nothing that begins in motion but there's ways around that, I have a volume per time rate limit and a range limit but they're big, I have to know what I'm making to pretty high granularity if I'm inventing it or be able to identify it by conjurable parameters if I'm copying it, I can do format conversion but not translation, and if I make animals they come out real dumb."

"Those are fascinatingly different from the limits on conjuration as we know it. Except for the part about animals; conjured or transfigured animals are in most cases extremely dim."

"An interesting commonality, that. Couldn't tell you if it means anything."

"Neither could I. There are theories as to the cause, on our end, but nothing definitive. More immediately, how did you come to Hogwarts?"

"Demons can be summoned. I didn't know there was something unusual about this summon till after I got here."

"I didn't know muggles knew how to summon demons. They do keep coming up with new things, don't they."

"This isn't the universe I'm usually summoned to."

She looks at the trio. "How do you three manage these things?"

Shrug.

Shrug!

"The book said it was a scrying spell!"

"It's very irresponsible of the author, may warrant looking into once the immediate mess is handled."

"Yes. The author may or may not have known what they were doing. I haven't heard of any spells summoning people from other realities before."

"Maybe it's some kind of fluke but it bears looking into."

"Yes. Magic often has strange results when things go wrong, but rarely this dramatic and this stable at the same time."

"The being summoned part is normal for me. Just not the destination or the wizards."

"Do you think it's reproducible here?"

"Worth finding a volunteer to check but in case something weird is going on I do want to look for a volunteer first."

"You can contact others of your kind from here? Have you told any of them about magic?"

"I can write them letters and they can make the letters when they check their mail. I haven't done this yet because the basilisk and also your fellow faculty member's unpleasant habits seemed like the priority."

"Witches and wizards have concealed our existence from all others for centuries, for our own safety. It would be unwise to disrupt that situation, even or perhaps especially with beings from another reality."

"...your safety from... people who do not have magic?"

"When the Statute was ratified, they outnumbered us three thousand to one. Now they have weapons that kill thousands in a moment, and outnumber us five thousand to one. Conflict between our peoples would be a catastrophe for everyone."

"Some people approach this sort of problem with, like, political philosophy."

"I'm not quite sure what you mean."

"It's not very high on the triage list, never mind."

"And here we are." She stops in front of a portrait of a large pink-clad woman, glances at Lockhart, and whispers something inaudible; the painting frame swings out to reveal a hole wide enough to climb through. Cam might need to pull his wings in all the way.

They fold up real small.

Inside are some people doing their homework, two boys playing cards, and the redheaded girl writing in a little black book in one corner. The boys look up at the two professors in surprise, and their deck of cards disintegrates violently.

Cam waves in a nonthreatening manner.

She notices him, blinks a couple times, notices Harry, squeaks quietly, and shoves the book in her bag.

...Cam attempts to conjure a copy of the book.

No sale.

"Book's magic. Or something else that foxes me but probably magic. I don't know how common that is."

"Miss Weasley, I need to speak to you for a moment. Please bring your book with you." She waves her wand and the wall acquires a door to a small office. The other children look torn between intense curiosity and "whatever trouble you're in, better you than me".

Cam will, uh, loiter awkwardly.

Just so long as he's loitering awkwardly inside the office where McGonagall can keep an eye on him. He and Lockhart can be Awkward Loitering Buddies.

"Miss Weasley, I'm going to need to take a look at that book of yours."

"It's my diary? Wh-why do you want to read my diary?" 

"I believe it may be enchanted in some way--perhaps cursed. If it proves to be merely an ordinary diary, I assure you I will return it intact."

"It's--I--oh, take it, I don't want it anyway, I hate it!" She grabs the black book from her schoolbag, shudders, and flings it at McGonagall, then turns to the nearest wall and collapses against it.

McGonagall levitates the book before it hits her, plucks it from the air--

And tosses it onto the conference table, shaking her hand as though bitten. "This is some extremely Dark magic," she murmurs. "Why Albus had to be at the Confederation this week of all weeks . . ." She starts moving her wand in complex patterns over the book and incanting something which, if Cam understands Latin, is gibberish that resembles a lot of words related to perception and detection.

Ginny turns slowly away from the wall, muscles twitching and clenching against each other, face slack and expressionless. She hisses like a snake and lunges for the book.

WOW okay how about her ankles and wrists are all tied together now, he doesn't know if drugs work on wizards. She can crash into a pillow here.

WHUMP. Facefull of pillow. Incoherent noises.

"That was Parseltongue--she said 'Come to me' and then 'Kill!'"

McGonagall opens the door to the common room and says, "Everyone into your dormitories immediately! Stay there until I say otherwise!" Students grab their things and start dashing up the stairs.

"Is there no plumbing in the dorms?"

"There is, but the wards are especially strong there. I hope it will be forced to come through the portrait. Mister Potter, go upstairs!"

"I think it is headed for the portrait--Professor, maybe I can talk to it, tell it to stop--"

He's cut off by McGonagall levitating him up the stairs and shutting the door behind him. She looks at Cam, seems about to say something, then thinks better of it and turns back to the entrance, wand out and face stony below the mirror shades.

Cam makes little dioramas of the basilisk's location. "Should Ginny also be upstairs, or...?"

"It shouldn't target her while she's controlling it, but it's not worth the risk." Ginny gets silencio'd and sent up the other staircase.

The basilisk has exited the plumbing and is heading up a familiar set of stairs and hallways. Very quickly.

"Here it comes."

CRUNCH.

There's a dent in the wall around the portrait hole.

CRUNCH.

The wall is a web of cracks.

CRUNCH.

A massive coil of scaly muscle busts through into the common room.

The thing is supposed to be able to talk, more or less, and Cam doesn't know how to go pharmacologically nonlethal. He settles for standing in front of Lockhart and being ready to interpolate it if McGonagall doesn't have an idea.

McGonagall has lots of ideas! She's casting multiple spells a second, beams of light and detonations and spikes shooting up from the flagstones to form a barrier of needles. 

None of it works. The wall of scales shrugs off the spellfire and crushes the spikes like so much rock candy. 

The King of Serpents draws back for a moment, but only to reposition itself. Here comes the head!

The head is going to separate from the body now.

The scales actually sort of manage to hang together around the interruption, but apparently it never occurred to evolution and/or dark wizards to armor the insides separately from the outsides. Now there is a dead snake pouring gore from its neck. 

(Lockhart uncurls a bit from where he had been curled up in the corner of the room.)

McGonagall takes a moment to breathe, then starts vanishing the blood and looks over at Cam. "That was you, I take it? One hundred points to--excuse me. Thank you for your prompt intervention."

"It wasn't that prompt, I was hoping you had a way not to kill it, since it talks."

"I'm not sure it could actually use language in the way humans can. Regardless, I fear I didn't have a way to subdue it fatally or otherwise. You saved a lot of students today."

"Incidentally, you have the right to the corpse. It's quite valuable; practically every part of a creature this magical has its uses in potionmaking."

"I do not know how to make potions. I suppose I could find a use for currency."

"It's up to you, though I will ask you to find somewhere to store it so I can make repairs to the tower. But I believe the next item on today's list of crises is that cursed diary."

"Unless you want me to wreck it like how I beheaded the snake that sounds like your department."

Lockhart is trying to sneak around the snake and out of the common room/hallway/rubble zone.

"You. I will see you in my office in three hours. Consider yourself suspended, and if I had any hope of finding a substitute you would already be sacked."

"How is he even sort of better than nothing? He attacked a kid! Give them a textbook and set them last year's exam and at least if they learn anything they'll remember it!"

"Once I know what exactly happened I might do just that. If it were any other day . . . . Mipsy?"

A small humanoid with large ears, wearing a toga made of towel, appears from thin air, goggles at the basilisk, and asks, "Professor McGonagall is wanting Mipsy?"

"Yes. Help mister Swan find somewhere to put this corpse. Don't worry, it's quite dead."

"I don't think I can carry it. Uh. Nice to meet you, Mipsy."

"Hello master Swan! Mipsy is moving your snake for you! Where is you wanting it?"

"I think I'm too old to be a 'master', isn't there a cutoff for that somewhat lower than a hundred and seventy-two? I am not familiar with many locations, perhaps you can suggest somewhere it'll be out of the way and convenient to anyone who wants to buy and make off with pieces of it."

She isn't quite sure what to do with Cam's first sentence, but, "There is being an empty storeroom near the kitchens! Is you wanting Mipsy to bring the snake there, or show you first?"

(McGonagall has gone back to the side chamber, and is doing variously destructive things to the diary, now sitting in a metal box, with no effect.)

"If you could show me that would be convenient."

"Yes master Swan! Right this way!" Mipsy heads into the hallway at a surprising speed for how short her legs are.

"Please don't call me that, it makes me sound like an alternate universe Batman or something," he says, following along. "Mr. Swan is fine if you prefer to be formal."

"Yes mister Swan!" Down several flights of stairs, pause to wait for the next flight of stairs to arrive, down that one too, through a door with the handle on the left edge, turn one-eighty degrees and go back through the same door with the handle on the left again to exit into a different hallway, four left turns and here's a door. It opens onto an empty room with shelves all over the walls but plenty of space in the middle.

When they reach the flip-door he creates a strange looking object, which sputters and smokes and sparks a bit before falling inert. "Any idea why my computer did that?" he asks Mipsy.

The elf looks dejected. "Mipsy is not knowing what a computer is or why it is doing that. Mipsy is sorry."

"No big deal, just means I couldn't take notes on the route. I can probably remember it. Looks like a fine place for the basilisk."

"Mipsy is bringing it here now, then?"

"Sure, thanks!"

Mipsy vanishes for a minute, then the basilisk corpse appears coiled up on the floor. It piles up most of the way to the ceiling. Mipsy's head pops out of the top of the coil. "Is here being alright mister Swan?"

"Looks good, I appreciate it!"

Apparently house elves flap their ears when they're happy! Or at least this one does. "Is you needing anything else?"

"I think I can find the way back but if I'm mistaken or the staircases misbehave or the professor has wandered off I'd appreciate an escort."

"Mipsy is happy to be of service!" And she can lead the way back to the common room. The route they take up is in fact different from the route down, though possibly the former way would have worked and this way is just faster. Also, the Gryffindors have clearly been let out of their dorms, given the knots of students excitedly spreading rumors that manage to be even weirder than the truth.

And is Professor McGonagall there?

She is! She has gotten the wall back together, but the portrait hole no longer has a portrait on it. The portrait is on the floor, and the fat lady in the pink dress is as still as, well, a painting. She's gone back to futilely trying to destroy the diary, which is now in a different, significantly thicker box on a table now sporting several injuries.

"Do you want me to try?"

"Please do. I have made Miss Weasley as comfortable as I can, but I can't release her until I've severed the connection."

How would this book like to share all its space with a similar mass of liquid nitrogen?

Now it's in a puddle of liquid nitrogen! Now it's in a vapor cloud. Now it's fine.

"I can start trying assorted acid or I could - if I can work around whatever went wrong with my computer - take it into space and feed it to a tiny black hole, but I'm not sure if I should expect that to work where interpolation failed."

"Electricity doesn't work in Hogwarts due to magical interference. I have already tried acid, I'm not sure what a black hole is . . . . Hm. How much ice can you create, how fast?"

"A lot? Uh, I think it's something like two hundred cubic miles per second at absolute top speed but I should not do that under most circumstances because it's hard to stop in the middle with suitable reaction time if you're going that quick, that's astroengineering speed."

"And you could create it in whatever shape you wished? For example, in a hollow cylinder, continuously renewed?"

"Sure, assuming it doesn't exceed my range which is a couple astronomical units. Uh, and I guess depending what you mean by continuously renewed, that seems like it might depend on whether any forces might change its direction or anything like that once it's made."

"In that case, if you are willing, we might be able to safely make use of Fiendfyre. It is a form of magical fire which can destroy even very strong magical protections. It is, however, extremely difficult to control. I would not ask you to do this if a student's life were not at stake--I believe the diary is draining her life force."

"Okay. Possibly, uh, not in the school."

"I was intending to use the lake."

"Sure."

Then if he's ready to do it now, they can traverse Yet More Stairs, and also 540 degrees of clockwise hallway with no apparent elevation change, and emerge via an elaborate entrance hall into the Hogwarts grounds. They're very picturesque, with an imposing old-growth forest on one side and a large lake on the other.

"Okay, how do you see this working?"

"You make an open cylinder of ice near the shore, I levitate the diary in and cast Fiendfyre, you seal the cylinder and keep replacing the ice until I can put the fire out, which I expect to take not less than twenty minutes and not more than two hours assuming it remains contained within the cylinder. With your permission I will cast some protective spells on you first." She directs her wand at herself, then at the Lakeshore, murmuring more not-Latin.

"I don't object, since I don't know how magical damage might interact with my being indestructible." Big ol' cylinder of ice.

McGonagall casts the protective spells on Cam, and summons a broom so she can see down into the top of the ice cylinder for better aim.

She tosses the diary in, hovers well back, counts down "Three, two, one, now."

And there is fire, white and gold and incredibly hot. Cam can feel the heat on his face from here. Ice starts flashing into steam in moments, and glowing through the steam cloud are the firey shapes of beasts and monsters, clawing at their icy prison, roaring, boiling their way out.

Freaky!

Cam tries switching to dry ice after a bit, ready to go back to normal ice if anything weird happens and wishing he'd asked about this possibility first.

Nothing freaky happens beyond what was happening already.

McGonagall starts fighting against the spell from pretty much the moment after she casts it. The flames slowly shrink, then flare up nearly as large as they started, then shrink again. She looks gradually more and more exhausted, and by an hour in she's started to slump down on the broom, but she keeps her wand pointed rock steady at the fire.

"Do you want... coffee or something...?"

"Coffee . . . would be . . . lovely!" She calls. It's clearly an effort to make herself heard over the fire.

She can have a lidded to-go cup of coffee with modest quantities of cream and sugar in her free hand, appeared slowly so she isn't startled into dropping it.

She drinks the coffee, slowly, and with her eyes locked on the fire over the top of the cup.

The flames shrink to the size of a bonfire, then a campfire, then a very angry candle, and finally dwindle into nothing. Not even ashes remain of the diary.

"Can I get you anything else? I wasn't expecting this to take that long." He wants a hot dog so now he has one.

She brings the broom down, dismounts, leans on it like a walking stick for a moment before slinging it over her shoulder and setting off toward the castle at a noticeably slower stride than before. "Perhaps a cup of tea? Cream, no sugar."

"Oh, right, this is Britain." Tea earl grey hot.

"Thank you. For the tea and for your assistance earlier. Miss Weasley should be safe now." She drinks the tea while they hike back to Gryffindor tower, vanishing the empty cup when she's done and pausing only to grab a portrait of an armored knight off the wall, explaining to it that it needs to fill in as Gryffindor password check for the rest of the term.

"Interesting security system you have."

"The Founders came up with it. Ravenclaw uses riddles, but the other three all have variants on passwords. Though Gryffindor is the only one which enforces it with a portrait."

"Does the portrait add much to the security? Do they recognize the students or something?"

"They can learn to, though there are so many forms of magical disguise that the password is still very important. The main benefit is that they move their own frames, which makes it harder to sneak in behind someone else."

"Oh, cool. I guess passwords probably work all right as long as computers don't."

"I don't see the connection?"

"Uh, when computers work a bit better than they probably do in this era they get good at trying a lot of passwords very fast and it makes it important to have heftier security but this is probably fine for your use case except when giant snakes bypass the password mechanism entirely."

"I'm not sure how anything could try passwords faster than the portrait can hear, but as you say it's unimportant. The Basilisk was the first security breach we've had in some time." She installs Sir Cadogan, lets herself and Cam in, and goes to untie Ginny Weasley where she's asleep on a couch.

The ropes vanishing is enough to wake her up. "Hmm? What--what happened? You wanted to look at the diary, and then . . . How much trouble am I in?"

"None anymore, as far as I can determine. You were being controlled by the diary, but it has been destroyed and the effects of the curse should fade quickly. Nonetheless you should see Madam Pomfrey."

She looks searchingly at Ginny. "How much do you remember about what the diary was making you do?"

Ginny answers, in a whisper, "I was attacking people . . . Justin and Colin and Mrs Norris and those roosters--I'm gonna be expelled!" She bursts into tears.

"There, there," says McGonagall a bit awkwardly. "You're not going to be expelled, it wasn't you doing it. But can you tell me where you got the diary?"

"I don't know. It was inside one of my textbooks when we got home from buying them."

"...do you shop at an evil bookstore?"

"N-no? It was the used section of Flourish and Blotts."

"Maybe they keep records on who donates them stuff or something. Probably not though..."

"And they probably get a lot of copies of A Beginner's Guide to Transfiguration."

"I take it you're interested in helping trace the book? Would you like an empty classroom to work in?"

"I couldn't conjure the book," Cam points out. "I can see if surroundings work though, sure."

"That could work. Miss Weasley, do you remember the date you bought your books?"

"It was the middle of August . . . it must have been the nineteenth, I remember because Professor Lockhart was doing that book signing."

"Speaking of him, where's he gotten to, I still have his wand but if he could swipe one or something..."

"You have--of course you do. He's probably trying to figure out how to get it back without losing face." She doesn't look amused, nope, definitely not.

"Why do you have his wand? And why do you have wings?"

"I have his wand because he Memory Charmed your brother Ron and I have wings because I wanted to be able to fly."

"Um. Okay. Is Ron alright? Is everyone else alright, I don't know what the--you know about the basilisk, right?"

"Yes, we do, and it's no longer a problem. Mister Swan here dispatched it."

"Wow."

"How are you holding up, you looked pretty badly off..."

"I'm--not hurt or anything? I just--Merlin, I was so stupid, I thought Tom was my friend!" She pulls her knees up to her chest and plonks her forehead on them. "He was so nice at first," she mumbles into her robes.

"What is even the motive to make an evil diary that possesses schoolgirls," wonders Cam.

"Perhaps Dumbledore will know when he returns. Can you tell us more about Tom, Miss Weasley?"

"He--he said he was Tom Riddle, and it was his diary from when he was at Hogwarts. He wanted to know all about what it's like here now, and about--about Harry Potter."

"...was Harry Potter somehow known when he was at Hogwarts, because I have met Harry Potter and he is not very advanced in his educational career at this time. How old a diary is this?"

"Fifty years. He didn't know about Harry before I told him, and then he wanted to hear all about how he defeated You-Know-Who. I didn't know how, of course, nobody does, that's just what he asked me about the most."

"Huh. Well, I can go attempt amateur forensics on whence it came. Do you want, like, ice cream or something."

She looks at him like this is probably a trick question, but says, "Ice cream . . . would be . . . nice?"

He gives her a little bowl of chocolate ice cream with caramel sauce.

She takes it, peers at it, and eventually deems it probably non-hazardous enough to eat a spoonful, and then another. That might be a hint of smile.

"Thank you."

This appears to have earned him some more metaphorical points with McGonagall. "Do you have enough to work with from here?"

"Think so. Obviously I won't recognize any bad actors who turn up so I'll need someone to identify them from models."

"Of course. Would you prefer to work in our library, or an empty classroom? I can't leave you in here unsupervised and I need to take Miss Weasley to the hospital wing and then deal with the probably former Defense Professor. Oh, and I'll need his wand back."

"Classroom is fine. What's going to become of his wand?"

"I'm going to return it to him, probably right before evicting him from the castle. Only extremely serious crimes would justify keeping it from him."

"...he erased a child's memory. With the wand, I'm not suggesting it as a punitive, it's a preventative. Is this like suggesting taking somebody's hand off in wizard culture or something?"

"Almost any wizard would rather lose their hand than their wand, even if hands weren't more easily replaceable."