"That's very clever in precisely the sort of way that would go terribly if you did it with anything related to magic. Congratulations."

"Worked in my timeline or I would have been more nervous, admittedly - why would magic go wrong if you tried something like that?"

"Maybe the male mosquitoes would turn female, or start having daughters, or start biting people, or there would turn out to be some other way people get malaria so eliminating the mosquitoes would only cure half of it, or it would turn out that catching malaria prevents some other, worse disease . . . I recognise that all of those sound ridiculous when applied to a well-understood situation. The real trouble is that with magic it's hard to be sure you understand it well enough to say exactly how something will go. But having seen it before is much more reliable."

"It... does sound ridiculous but I'm really curious about what underlying - chaos or confusion or something - is sowing such difficulties in the field."

"Mostly it's that magic is extremely complicated, especially when large amounts of time or distance are involved. The larger a spell, the larger the second order effects, and third and fourth and so on. Many wizards have attempted to find patterns that would make those effects predictable, but so far there is no substitute for careful observation."

"So it's sort of like trying to predict the weather...?

"Septima, you and me have got to have a great big sit-down about magic and math and computers."

Septima: "Ooh, yes! I keep wanting to buy one but I don't have anywhere safe to put it, and also Charity tells me they keep making better ones so I keep putting it off."

Filius: "Yes, that's a very suitable analogy."

"They do keep making better ones and will never stop but I can skip you ahead a few generations of design and you can keep it at my house. They can predict the weather and stuff!"

All of the professors are excited about this prospect! It's possible Sybill Trelawney will also be excited about it but most likely she'll hate it. They should probably tell her anyway. All of them look at each other in some sort of combination "game of chicken" and "calculation of who owes whom a favor" and Vector volunteers to tell her if initial experiments seem promising.

And eventually they touch down, and soon enough the train rolls in. (Cam has come to acknowledge that "shirtless" is not professional attire, so over his jeans he's wearing robey thingies that button below the wing slits and have a vent in the back that lets his tail out.)

None of the first years see him until after they've seen several ghosts, and the singing hat that promises to analyze their souls is more interesting, but he still gets a few stares. Maybe for the wings, maybe for the rumors that he's a half-dragon squib who killed a basilisk with a weapon he stole from a secret death eater; it's hard to say.

The eleven-year-olds get Sorted. The feast is delicious, for whatever that's worth.

His first class of the semester is the next day, and it's the Slytherin third-years. Generally the only Slytherins willing to stoop to taking Muggle Studies are those with sufficient academic or spellcasting difficulties to have no priorities in their elective picks other than "easy", but Professor Swan is interesting. The section has an entire six students despite it being the class of '97.

One of them is a white-blonde boy flanked by two hulking goons thirteen year old boys who would quite like to be read as hulking goons and are making a solid effort in that direction. He looks curious under a thick layer of disdain; they appear to have followed him in on autopilot.

"Good afternoon! My name is Campbell Swan, and you are... yes, one two three four five six of you. Please write your name on the little rectangle on your desk and then peel it away from the backing - fingernails help - and stick it to your robes unless you want me referring to you by charming nicknames I make up for the next few class sessions. I have been gently advised to make you all call me Professor Swan but I am a barbaric American and will not mark you down if you let slip a 'Cam'. For this first lesson we're going to a bit of a diorama I've set up, out on the grounds. On future days marked with the same symbol as this one on your syllabus, you may bring a broomstick to class if you prefer, like me, to skip the staircases. Meet me at the north shore of the lake."

He opens the window.

The two girls and the short dark-haired boy label themselves Greengrass, Bulstrode, and Nott respectively. The two aspiring goons look at the blond boy, who decides they are all too cool for this name tags business but announces aloud that his name is Draco Malfoy. And then stares because the professor is maybe going to jump out the window for real.

The professor jumps out the window for real! "See you in a minute!"

His wings snap open and he can be seen swooping away.

So far taking Boring Stuff Nobody Cares About studies is working out pretty well! They all tromp down to the exit and head towards the north shore of the lake.

Cam meets them there outside a beige house with a garage door and an orange tile roof and a mailbox.

"This is my house. Or rather, it is a copy of the house that I occupied when I was your age, in Phoenix, Arizona, in the year 2000, in my timeline, a hundred and fifty-nine years ago. Except for some redactions for privacy, and a few safety features so you kids don't electrocute yourselves, the whole building is exactly as it was then complete with all its contents. This means that some things are a bit ahead of what Muggles in this timeline are doing today, but not by very much; I grew up on a limited enough budget that we didn't have the latest of everything and most of it would have been available in 1993 or is in fact identical to what the house contained in 1993, except for the books and movies. I have labeled the most conspicuous anachronisms with stickers similar to your name tags. I have labeled a bunch of other things with stickers too but the anachronism stickers are pink. If you find one I missed I will give you a point and nobody else has been through here yet, so you get a head start. Could I have made the house as it was in 1993, sure, but then the selection of kid-friendly entertainment would have been a bit below your level and I doubt any of you happen to share my mother's eclectic taste in romantic comedy et cetera. Questions so far?"

"Is it true you're not really a wizard?"

"Can you explain the whole, timelines being ahead of each other, the year two thousand being a hundred and something years ago, thing?"

Pointing at Draco. "That is true, nametagless boy! I am a demon instead." Pointing at Greengrass: "I can't really explain that in terms of why it happened but what happened is that I was chugging along in the year 2179 and a magical event that would have brought me to 2179 Earth brought me to this Earth instead. It seems like it has more stuff to do for my personal taste in stuff-doing than mine did so I've stayed."

He steps up onto the front walk and takes the spare key out of a potted aloe. He unlocks the door and pulls it open. "I know Gringott's has keys, but do you bother with them when you're not going to do an entire magical situation, given that there's a lock-bypassing spell? Keys work mechanically, when nobody's got magic." He replaces the key in the aloe plant and waves them in.

"'Nametagless boy', really? I know you don't know anything but you really need to know the name Malfoy. And no, no-one whose house has proper wards needs to use keys." He strolls nonchalantly into the zoo exhibit house. 

"Dragon Malfunction, thank you for the opportunity to demonstrate my planned assignment system!" He appears a book entitled Locks: How Do They Work? and presents it to Draco with a flourish. "Your own personal first assignment will be to convince me that you read this book, which you may do by means including but not limited to oral report delivered at any time of mutual convenience, written essay, demonstrating the ability to nonmagically pick locks, or manufacturing a functioning lock and key system of any sophistication level covered in the text."

"Dragon Malfunction? Really? And why should I have to do extra homework?" He passes the book to one of his minions.

"Let me know when you want a replacement nametag. It's not extra! Everyone gets assignments, and you will be scored on the total number of them you complete. You get to pick your own assignments by expressing curiosity, incredulity, contempt, confusion, fascination, or none of the above so I have to make something up. You are the only person whose assignment is locks. You can pick up zero or a dozen more assignments today; doing more now buys you slack for later and if you really hate one all you have to do is stare at the refrigerator for a long time, or demand to watch the second episode of Jurassic Park after we see the first one and you'll have an alternative to replace it. Getting an A calls for doing an assignment every week on average, and an O calls for two. Everybody follow?"

Bulstrode's brow furrows. "Will you tell me what mark I'm on track to get, if I lose count in the middle of term? And does it really only matter how many I do and not what mark I get in each one?"