And the door opens and someone who is too old to be a student and too young to be a professor and too winged to be a human walks in from somewhere else entirely.

"- Timothy, nice to meet you, am I off school grounds somehow?"

"What."

"...Timothy Laurence Way, I thought that Hogwarts had decided to shuffle up its study nooks but you don't look like you go to school here."

"...okay, if the idea of naming a school 'Hogwarts' counts for half a point this is two and a half kinds of bewildering." He glances at the exploding stars. "Three."

"You haven't heard of Hogwarts? ...are you from the colonies or something, you have a fascinating accent. And you still haven't introduced yourself -"

"...I have not heard of Hogwarts, I am originally from the United States, and my name is Campbell Mark Swan if we're doing full names."

"Originally? Have I discovered a portal across the Atlantic or not, that would be kind of a big deal."

"...you have not discovered such a portal unless it is more kinds of bewildering. God this is weird."

"Two and a half ways so? Do tell."

"It's probably more ways than that for you if you refer to the States as 'the colonies' unironically, I'm not even sure where to start."

"Hmm. I am a student at Hogwarts, the preeminent - really, the only - wizarding school in Britain; it is a magical castle with staircases that occasionally run different ways on Thursdays, rooms that appear only when you need them, and enough other oddities that when I noticed a classroom was - this - instead I didn't think much of it. The American Muggles did have a war over independence recently, the wizarding world's a bit behind the times -"

"The last time I checked Earth was experiencing the year 2179; I have been away from any ability to verify that for a few years but doubt it went backwards and doubt further that it acquired wizards in so doing."

...blink. 

"...I should get my dad or my little brother in here and you should teach them three hundred years of Muggle science, except it probably won't work in Hogwarts - do you have books or something for it -"

"What is a 'Muggle'? - and I can acquire books."

"People without magic - most people, that is -"

"...I do not think you are from the same Earth as me."

"Magic is secret - has been since the 1600s, there's an international law against doing magic in the presence of Muggles or otherwise permitting them to learn that it exists. But I'd put a lot of money on my ability to end the Statute in the next half-century and it is hard to imagine it'd still be present in - 2179."

"That and magic was de-secreted where I'm from in the early 2000s, and it was less 'wizards' and more 'summon demons to do your bidding'."

"- yep, we don't have that. ...sounds like kind of a bad idea, honestly -"

"Works out okay most of the time."

"Demons don't exist here. There're dragons and merfolk and goblins and vampires and werewolves and banshees and centaurs and elves -"

"Yes, that's another form of bewildering, I know someone who looks and sounds quite like you apart from being an Elf."

"It's uncanny."

"...I'd be an appallingly bad elf."

"Might not be the same kind of elf what with the not the same world thing. My Earth doesn't have Elves, I ran into Elves elsewhere."

"...are all of your elves slaves magically bound to the household their grandparents served in?"

"No, my Elves are tall unreasonably pretty people with pointy ears and brain backups who sing a lot."

"We should pick a different word for those two species, those sound like some important differences there. Brain backups?"

"Quendi for my kind, then. I don't know how to explain the brain backups from a tech background of 'the Revolutionary War was recent'..."

"It's 1802. Uh, what implications does having a brain backup have -"

"They can be brought back from the dead."

"Ooooooooh. Can I have one?"

"Doesn't work for humans and even if it did it's more complicated than that."

"Ah. Okay. What sort of things do I get up to when I am tall and pretty and have pointy ears and sing a lot?"

"Well, when I showed up there was a war on, so that."

"Ah. - is there still in fact a war on, if you don't have any wizards we might be able to help -"

"It's over now."

"Do you want to talk about it -"

"It's not really my fondest ambition but you apparently have magic so I might find it necessary to tell you for context."

"If you wanted magic help with the war I would in fact demand a lot of context. Magic help with reconstruction or something I can do no questions asked."

"Reconstruction is underway. Although you probably can't do the part I'm most hoping to turn up because you were very excited about Elves being able to come back from the dead so that's not customary for wizards."

"It is not. Though if anyone could figure it out it'd be my father."

"Yeah, assuming you're not just a lookalike I'd believe that."

"Does the person who looks like me have six younger brothers?"

"Yes."

"...huh. Anyway, my father's trying to reconstruct the Philosopher's Stone, an old lost piece of magic that does immortality; if he gets that he'll probably try for resurrection next. The Philosopher's Stone has at least been accomplished before; resurrection no one's ever done."

"It'd also have to be a sufficiently generic solution to bring back dubiously material magic god things."

"I mean, we wouldn't want something that's only humans, but we don't have any dubiously material magic god things. ...if they're gods why do they need resurrecting, what kills a god -"

"Anyway, I can ask him. - we're talking decades, if it's achievable, possibly longer, the original person to make a Philosopher's Stone was a hundred and thirty when he finished it -"

"Elves're pretty patient and I'm not even done putting those back yet."

"How many people died?"

"Fifty-five million all told. I can put most of them back."

"I'm glad you can do that."

"Elves." Shrug.

"So, uh, how about those books, Minor's going to get himself expelled by the end of the week but it's probably worth it -"

"It'll take up a lot of room in print, might make more sense to teach you to use a computer."

"Sure, what's that?"

He has his; he pulls it off his belt, turns it on. "Information-handling technology."

"Oooh, cool."

"Yeah. This model requires brain surgery, don't know if wizards have weird brains or anything, probably shouldn't risk it."

"Brain surgery? And I don't know either - we can interbreed with Muggles -"

"Little metal thing in my brain tells the computer what I want it to do. Fantastically convenient, necessary for heavy-duty information security, and if you have a Wizard Cortex or something where your medulla is supposed to be then trying to give you a chip could be all kinds of problematic."

"Okay. Yes, I will decline to be the first test subject for that. It'll be hard to talk my father down from it, though."

"Unless I need to worry about mind control wizardry he doesn't particularly have to agree, and if he's inconvenient about it I'll distract him with a language he doesn't speak or something."

"There's mind control wizardry but my father is not in fact evil. ...distracting him with a language he doesn't speak would totally work."

"Although I don't want to pause too long in the Elf-resurrection I was doing. Someone will wonder what's keeping me any minute and 'looking into otherworldly magic that might get the Maiar back' is a better explanation than 'teaching an alternate universe Fëanáro a language'."

"Fëanáro, huh."

"Yeah. The one who looks like you is named Nelyafinwë Maitimo."

"What about the rest of my family?"

He has notes. He pulls them up. He reads them off. "- don't think anybody ever mentioned the mother's name or if they did I didn't write it."

"...huh. Okay, sorry, I'll let you get back to work - unless I can help somehow -"

"I don't know if you can, all you've mentioned about what wizards do is architectural or speculative."

"Lots of varied and creative ways of doing lethal or nonlethal harm to things, making things, moving things, transfiguring things, divination but it's unreliable, potions, Apparation - huh, I could check if I can Apparate here, if I can that'd suggest it's not in Hogwarts - which the computer maybe suggests anyway -"

"What is Apparition, what sorts of things do potions do, how unreliable, how does the computer suggest that?"

"A few years ago some Muggle scientists came up with this idea called voltaic piles, they work with metal, that's about all I know but my father thought it was a big deal and immediately replicated it and when my little brother was trying to do the same he discovered that whatever physical principles makes voltaic piles possible, it doesn't work within Hogwarts because of the protections laid on the school thousands of years ago. It stands to reason that complicated future Muggle technology is at least fairly likely to stop working in Hogwarts, and it worked fine. Apparition is -" he twists in place and disappears, reappears across the room with a pop. "Potions can make you look like someone else, heal things, shrink things, induce or cure a variety of conditions, let you breathe underwater..."

"...what's the range limit on Apparition?"

"Depends how good you are and how tired you want to be and if you're taking people along but very few people can jump the ocean."

"Ah, damn."

"Where would you want it to go -"

"It wouldn't help with the dead people - well, probably, they're immaterial by default and if teleportation is possible in principle maybe they could be extracted and be just fine? Not sure - but it'd speed up interplanetary travel, if it reached that far which it doesn't."

"Interplanetary -"

"The other you's dad invented faster than light travel."

"I feel like I do not know enough things to appreciate how this is remarkable."

"On my Earth, that has not been invented yet as of 2179. Although there are colonies on the Moon and Mars."

"Ah. Cool. - if a werewolf lived on the Moon - no, you said you don't have any -"

"We do not." He approaches a barstool, apparently having decided that the conversation is going to continue long enough to warrant sitting down. A napkin appears and he blinks at it.

"I didn't get one -" He lifts up his rune charts - "oh, wait, yes, I did, and I didn't see it - oh, sorry, Bar, nice to meet you -"

It's quite all right.

"Are we intruding? What is this place -"

It's called Milliways and you are quite welcome.

"How'd you land on us in particular? Do you know anything about the tall singing Elf who looks like me?"

The door's whereabouts are quite outside my control and I don't believe I'm acquainted with your alt aforementioned.

"All right. I'll have a butterbeer."

Butterbeer appears!

"What an... evocative name for a beverage," says Cam. "I am sort of outside the market for free drinks."

I would be happy to recommend something unfamiliar.

"Okay."

He receives something unfamiliar and evidently likes it.