Someone opens the door. "Uh, hi? What's going on? Something interesting, for sure, but what is it?"

"A break from drills and a free drink! At least, that's what it is for me. This is Milliways, the interdimensional bar."

"Ooh, do I get the free drink? Also, drills?" She inquires. "Oh, and my name is Amy."

"Everyone gets a free drink from Bar, who is a person and also a bar. I'm Gren. Drills are training. My kind of witch loses power fast when we get older, so if you're going to help save the world you join up early."

"Oookay then. Nice to meet you, Gren. Training for what? What are you saving the world from? Can I help?"

"Nice to meet you too. I'm training for the Witch Wings, magical military. Neuroi, are flying monsters that appeared from nowhere and started blowing everything up. I'd love some help but what I dunno what you can even do."

Oh. "That's really sad. I can do magical items, stored spells and potions, but I'm not entirely sure what would be most effective here. I could get my friends to help too, probably. What's the most effective strategy against them that you already use now?"

"Bombs, followed up with starbursts? A magical attack. They're not that tough, but they regenerate quickly."

"Okay, attack spells that work really fast, possibly potions. What's your weakness? I imagine they're slower than you, right? How do they attack? Are you good on defence?"

"I think our biggest weakness is lack of endurance. Our kind of Witch can run out of magic, fights use a lot of magic. Neuroi vary a lot, fast, slow, big, small, maneuverable or not, tough or weak. Their attacks are either physical blades, not that common, or glowing red beams of light and heat. We're okay on defense except for the endurance thing." She demonstrates with a little shield, two rings of blue with vaguely rune-like symbols attached, spinning in opposite directions.

"Mmm, okay, I could call in Flora, she might be able to figure out how to fix it."
She trots to the door, opens it, and shouts, "HEY FLORA, COME LOOK, IT'S IMPORTANT AND NOT A PRANK, I PROMISE!!!"

Flora peeks in. "What's going on?" she asks, confused.

"Whole world's looking out on how to fix it. I'm gonna be buying science books, pricey as they are, bar knows about technology that's waaaay better than ours. Hi Flora, this is an interdimensional bar and I'm very glad Amy agrees that my world could use a little help!"

"They're at war with monsters that fly and shoot beams of light and heat and destroy everything. Gren here is magic, but a kind of magic that quickly fades with age and runs on some sort of magic resource. Can you do your analysis thing and maybe fix stuff?"

"Alright, I can do that, just let me summon my notes, I think I left them out." She pokes her head out of the door, and casts, "Accio analysis notes." Pieces of parchment come floating to her hand. She reads them for a while.

Amy decides to make some magical items for now, including stored runic cutting hexes, and some destructive potions that are relatively easy.

"We each get a few generic things we can do, then a special ability, not like your kind, smells like you can do anything with enough practice. Oh, my special is copying."

"Not anything. There are a few hard limits." She is sad at that part, but cheers up a bit. "So what I'm making now is magical items that can be charged up and will slice the thing you aim at when activated. To activate, say the thing written on them, precisely and loudly for best results. I'll teach you to say them a bit later. Then there's the potions, spill them on stuff you want destroyed. If you think of specific effects you might find useful, tell us."

Read read read.

"Communication stuff. Teleporting. Healing. Magic coffee?" She turns back to her own borrowed books. She is reading, apparently, about revolutionary technological advances such as vaccines and washing your hands, lightbulbs, and refrigerators.

"I could do a pair of mirrors that can communicate between each other! Portal rings, those too, but they're harder, we might need to work together, even call in other people. Healing, yes, healing potions are nice and easy! Alright! There is in fact a thing that could be called magic coffee, but I'd need to look that one up. I can also get you tech with some finagling, just produced for free. Oh, and large amounts of our magic break tech. So we should probably get them separately."

Flora has finished reading.
"Just a thing to remember: don't overuse the magic coffee, it has side effects just like the normal kind. Actually, take notes of everything, starting with that. Let's make a to-do list, task allocation, things and people we need to get, all of that. Oh, and I'm ready to do the analysis. Are you ready?"

"Sure, notes. Bar, paper and pencil? And another smoothie?" She tosses down some coins. Bar provides. Gren starts writing down things. "What exactly is your analysis going to be looking at anyway? I might be able to help."

"Where the magic is, how it works, a bit of everything. It might find out new things, it might not. Works better if you describe everything you already know beforehand."

Work work, lots of healing potions, they're nice and easy.

She has been moderately distracted by the magical goings-on, but they're not really copyable.

"Right... It's totally random, not passed on in families. About one in five hundred girls, but not in boys. First signs when you're ten to twelve. It's mostly intuitive, when we're using it, learning, practicing, doesn't help much... Specials can be just about anything. Magic items of any kind are extremely rare, in my world, legendary even. Trying to think if I'm forgetting things."

"Alright. Anything you can add before I cast?"

"...Flying! How do I explain flying? We can fly, but only on tools. Brooms are the classic choice, but they're actually really hard to balance on. They make special not-brooms that are faster, more stable, that kind of thing. But the flight comes from the witch, not the broom or not-broom. That's all I can think of, I think."

Flora casts, bringing her wand around Gren and then herself. What does she see?

It has a sort of simple elegance to it. A sharp line of power branching out and blossoming. The magic originates in her body, seated somewhere deep inside and strongly interconnected with the concept of life, though exactly what the connections are is not clear. The magic's core structure is clear and strong, shining starkly as if in defiance of the laws of physics. Flight, shields, strength, light and blasts - these things are brutally simple, hardcoded in a way. The edges, however, are - shifting. A confusing blur of nodes and connections and colors that change even as she looks at them. After a few moments part of the periphery becomes a miniature version of the core, with a miniature version of the core, with a miniature version of the core, repeated until it's too indistinct to tell. That part is probably Gren copying the analysis, from context.

How fascinating! She stares a bit more, what's in the confusing blur? What are the connections?

The confusing blur has- A cleaning spell. Electricity. Enhanced sight. Something with light. Elementalism. Telekinesis. Healing. Invisibility? Strange sensing powers. Something to do with crystals. Bits of this and that and everything. They feel things-Gren-has-copied.

The connections remain thickly overlaid on each other, but there are strong overtones of - children, motherhood, fertility, a cycle like a brilliantly blooming flower that will inevitably wither when its time is done.

Fascinating! "Your magic is connected to fertility in some way. I wonder if a fertility spell would help an aging witch? Do you want to get someone to try?"

"That's... Kinda strange. I'd get someone but I don't think I can. Bar took over the inside door of my room."

A napkin interrupts, To clarify, I do not control the movements of the door. My apologies for the inconvenience. As I said earlier, it will usually be the same time in your world when you leave as it was when you entered.

"I could take some of these potions and try them. Witches can already transfer mana, er, magic fuel to each other, it just takes gold tools and is kinda inefficient. Too bad there's apparently no way to know how often you'll find Milliways."

"What if we could make it more efficient? Can I analyze that?"

(Amy has done four healing potions, seven runic cutting hexes, and a mirror pair that she is now thinking of making into a network.)

"Sure. I need to borrow something gold, silver, or gemstoned."

Bar will provide if Flora and Amy can't.

"I wouldn't like to try anything transfigured before I know a bit about it, but I can buy something for you." She provides however much money is needed to Bar. Unless it is a very high number.

Bar indicates, 1 galleon for an inert gold ingot. I will happily reverse the trade when you are done with it.

1 Galleon it is.
Analysis stare!

Gren pushes a little mana into it.

Something about the fact that it is gold is giving it ability-to-hold-magic. Some of the magic just disappears when it goes in. It seems like various other stones and metals could work, or modifying the can-hold-magicness of the gold.

Can she change or imitate the can-hold-magicness with her magic, pray tell?

It would be tricky. A shortcut may be available: The gold's can-hold-magic is not 'dense' enough to 'fill' the gold. Increasing the magical property is already there would be easier than trying to change how it works or imitate it on something else, and such a procedure could help it store more before leaking, and would increase its efficiency as well.

"Hmm. I could increase the amount of can-hold-magicness in this gold, apparently. Hmmm. Now that I know what it looks like, let me try transfiguring gold, if I can do that I would rather get my Galleon back."

"It's your money, certainly. I'm wondering what kind of technology you have, not just magic. The stuff in my world is not very good, if Bar's books are anything to go by."

She takes a napkin and transfigures it into a chunk of gold. "We have computers and cars? But our tech won't work if we're going to get you a lot of magic stuff, so you're better off either doing that later and somehow getting someone to take the magic stuff away or just taking textbooks. I can suggest a few, but not that many." Finished. Analysis stare. Does this gold have can-hold-magicness, pray tell?

It has... Almost zero can-has-magicness. Not exactly zero, but nowhere near enough to be useful.

"Tech that the whole world can use probably does more good overall than a few thousand magic items, if you even make that many."

"Transfigured gold almost doesn't work at all. I will work on a spell to increase this gold's magic- no, mana holding ability, if we can get it in rune form then it'll be useful. Oh, wait, I've been operating under the underlying assumption that your world has ley lines. Does it? If so, we do actually need to call in someone who can go get either books about tech and science, or book recommendations."

Amy is at the other end of the bar, making more stuff, mostly re-useable (specifically in a world that has ley lines).

"How do you check for ley lines? I've never heard of them."

"We could use the traditional complex ritual or we could just leave an uncharged self-charging magical object out there for a while, and see if it works afterwards? Away from the door, but leaving it open would do, I think."

"I think I can hold the door and miss a training session for something like this. Ooh, and if we can get someone's attention in my world I can definitely find someone to pay you for all this stuff."

"I can use the amplifying charm, but if your door is the only door to your room, how is the person going to pay me? Unless you don't mind a hole in your wall or you have a big-enough window? In that case, we can test the fertility spell too."

"If you're going to Sonorous anyone, it better be me! I almost never get to do it!" Amy exclaims.

"Oh yes, of course, I forgot, the quidditch matches aren't enough for you."

"Holes in the wall are kinda cheap. Paying you for stuff that could turn the balance of the war is worth a lot. Same with testing things that might or might not work. Say, I think I might be able to make a potion. Whatever you're doing to the mix is registering on my copysense. Sonorous is a louder-ifiying spell?"

"Yep!" She grins.

"Alright, we could try one that's relatively fast to make, let me see..." She thinks for a while, then asks Bar for a potions book on her tab, and opens it to the right place, providing the ingredients.

She does step one. But what exactly is she making, pray tell?

She is making Murtlap Essence, according to the book. The instructions are a bit complicated, but fast to complete.

Cooking is not exactly something she's trained in before. At least it's short. "I'll need to borrow a wand, if you don't mind?"

The large, oddly-placed bruises on the inside of her forearms are suddenly more visible when she turns and holds her hand out.

"Of course," she says, and hands it over. "Um, why are your forearms bruised?"

She snorts. "Because that's what happens when you hold them the wrong way while practicing archery."

She closes her eyes and focuses on what she read off of previous examples of wand-use. Wave. That wasn't quite right. Wave. There we go. On with the instructions.

The potion begins emitting yellow smoke, which means: 1. It is almost done. 2. It is working.
"It's working, wow. Murtlap Essence can help with scratches and bruises, if you want?"

"Oh, definitely, yes. I don't think I'm even using the wand, though... Like, any piece of wood will do. I copied what the magic did after it came out of the wand, not before. Interesting."

"That is so cool! That means you'd go through Hogwarts in a breeze! Or maybe not, if you'd have to copy each spell independently..."

"Yes, a wand primarily channels and shapes the magic, to put it simply, so, that makes sense."

"And I have to remember the structure of it, too. I have, like, ten pages of notes on Sami's super-sight thing."

The murtlap essence looks done, according to the instructions. "How do you use it? Just sort of slather it on cuts and bruises?"

"You could do that, but having it totally covered somehow -- helps much more. Try tying a wet-with-the-potion cloth around the bruises."

"Huh, alright. Bar, could I get two arm-sized bandages?"

With or without adhesive?

"Uh, without."

£0.12. It appears.

"Thanks." Gren counts out coins, applies potion to the bandages, and starts wrapping her arms.

A napkin reminds Amy that she never actually claimed her free drink and asks Flora if she wants one.

"Hot chocolate with marshmallows, please."

"Something we don't have in my world, please!"

Flora gets a mug of rich, sweet-smelling hot chocolate at exactly the right temperature, with five small marshmallows.

Amy gets - Something bright orange with swirls of yellow and green, condensation forming on the glass. When the liquid hits her tongue it briefly crystallizes into fruit-flavored ice before melting, changing flavors as it does so.

Sip. Mmm~ "Thank you, this is really great."

Sip!
"Oooh! Thank you!! I have got to take some of that stuff home, it's amazing!!!"

Somehow the napkin that answers them expresses the emotion 'pleased'. You're too kind. Amy, I can certainly provide you with however much you want but I should warn you that it loses much of the effect if served warm.

Gren starts asking Bar to quote prices to buy textbooks - medical, engineering, electrical, mathematics.

Such books would start at about £40 each. The entire list would cost at least £1500, depending on the particular books I choose. Gren flinches at the number. It's almost enough to buy a house! My apologies. I am obliged to charge significantly more than average for books of a technology level higher than your own, especially many years higher.

"I have the Chilling Charm, so I'm fine. How much pocket money do I even have left? Hmm. How much for a case of that stuff?"

"Hmm, Bar, what if I asked the prices for all the same textbooks, also in Gren's money so as to not deal with the finicky conversions and time weirdness all at once, for myself?"

To Amy, Eight sickles, six knuts for a pack of twenty-four.

To Flora, I try to discourage excessive arbitrage. One or two instances is acceptable, but do be aware that I may have to stop if you get carried away. That said, £155.

She returns the forgotten potions book, which is absolutely undamaged. Her tab is now 0.
She quickly converts the £155 to wixen money in her head, just in case it isn't as bad as it sounds, (it's worse) and... thinks about how to cheat.
I need to get the information to Gren's world, not specifically the books. So, if I put them on my tab, and find a way to re-record them... Was there a spell for that? Duplicating, doubling-- aha, the Doubling Charm, she remembers.
That one was a hard one at the best of times. I need my notes.
She summons her notes again.
"I may be able to make temporary copies of any books we get on our tabs, but it's a really hard spell. I've got to read the notes first, of course, as always, and practice on something else a whole lot of times."

She counts. "Uh, I've got enough for a pack of twelve, in that case." She slides the coins over.

"Uh, hey, I will totally knock a hole in the wall and get someone from the government with government money to come here, we don't have to cheat too hard and I can pay you for all the magic stuff. Amy, I bet they'll buy you a year's supply and then some for all the potions and the communication mirrors and cutting runes and so on. Bar says she can drain money straight from bank accounts."

"Ooh, okay. So, will we first check the ley lines or call in someone else and break down the wall?"

"If that happens, I'd like variety, not just the one thing I liked."

"May as well do them at the same time? This is exciting, new magic."

"New magic is very exciting, yes," she says and smiles.

"Alright, let us through to your room, then."

So she stands up and walks over to the door and opens it to a very... Plain-looking and small room. There is a small, dirty window overlooking some kind of town or city. Not much detail is available; It's foggy.

"You'll probably need the shouting spell, to get anyone's attention."

"Sonor-"

Flora grabs her arm and raises her eyebrow.

"Oh, wait, I should probably cast on you, I'm not sure a random voice would be trusted." She sighs. "Sonorous!"

"CHIEF LAWRENCE! THIS IS GREN! I FOUND A NEW WEIRD MAGIC THING! IT'S ACTUALLY USEFUL THIS TIME! IT TOOK OVER MY ROOM'S DOOR, BREAK DOWN THE WALL!"

Aaaaand now we wait.

"I think it might be better to break the wall from this side, this room is pretty small, after all. Does that sound like a good idea? Or is there a chance of the corridor getting blocked, or something?"

"I was thinking of smashing into the room next to mine. We don't own 'em. But going into the corridor will work, too. Can one of you do it? Bar said I have to keep holding the door or it'll stop existing when I quizzed her earlier."

"I wanna!"
She casts a few Cutting Hexes at a wall. There is now a hole in said wall!

There are some confused-looking people dressed like Gren, whose reactions seem to be variations on 'Gren's doing weird things again'. And shortly thereafter, there is a very prim-and-proper older woman and a buff-looking moustached man in very bright uniforms emblazoned 'UDF'.

"Hi, Chief Drill Sergeant Lawrence and Senior Drill Sergeant Hamil. This is Milliways, and these are Amy and Flora. They've offered to sell magic items to us."

"Yup! We sure have! The Neuroi sound really bad."

"We're going to check if you have these things called ley lines in your world. If you do, the items that aren't potions are reusable and Gren can make more potions, apparently."

The Drill Sergeants glance at each other. The woman eventually says, "Miss Nylund, you're sure this is safe?" Gren nods. "Then I suppose I'll come in while Lawrence starts today's training."

"We need either you or me to hold the door open, so we can see if their thing charges. Time in our world will pause if it closes. I'll do it, I guess."

"...Alright, do so. And summarize what you've found here so far." Gren starts rambling, summarizing Milliways and her conversation with Flora and Amy.

Amy puts an uncharged communication mirror in the far corner of the room, and listens.

Gren is speaking more formally than she has in their entire conversation so far, and clearly trying her best to remember all the little details.

And then Gren is done reporting things. "Amy, Flora, anything to add?"

"What's there to add? We can help, so we'll help."

Sergeant Hamil has lots of questions about how their magic works, what else it can do, what the limits or hidden dangers are, and is willing to drink a fertility potion as a test. Also if they can produce something that grants haste, enhanced concentration, or similar, that would be great.

She looks at what they've already produced so far and offers an amount that Bar translates to... Almost 200 Galleons.

Flora is happy to tell them all about things like that, especially the Wit-Sharpening Potion.

"...Wow... I could get all of the books."

"Woah, thanks!"

She is briefly surprised they accepted what she considered a rather low opening offer with glee. She immediately arranges not to look surprised. "That's if a few tests on whether it works as described bear out, of course. Those cutting hexes in particular will only be useful only if they charge over time as expected."

"Of course."

"Unfortunately we don't know whether the teleporters we have access to can cross worlds, so this may be our only opportunity to trade with other planets. How long can we convince you to stay and continue making things?"

"I think I can stay maybe 4 hours? With a nap. Making potions too long tends to make you tired."

"I don't really know. Might become tired in 5 minutes, might become tired in 5 hours."

"If it's limited like that... Hm. Well, it'll still be a great help, of course."

"And the bar is a person! She can sell us books from the future. Well, so to speak, books from technologically advanced places. Pricey, but she can take from the base's account directly apparently."

"We are also more technologically advanced, so that's another way we could help."

"I do believe I'm <i>very</i> interested in technology. We have... Trains, basic vaccines, crude guns, compasses, mechanical clocks, natural gas lighting. Does that give you an idea of the kind of technology we might benefit from?"

"I'm not an expert in it, but I think after those it was telephones and airplanes? Those are useful, anyway, I suggest getting books on those. I can even explain airplanes a bit because I was interested in them for a while and I researched it."

"We won't have a use for airplanes, I suspect, but some of the design principles may still apply. Witches fly, and can lift fairly heavy loads while flying fairly quickly."

"No, I bet it can totally help. Show them how we went from brooms to the 'wings maybe, see if plane-shapes might do better."

"Airplanes are really big, though."

She draws an airfoil shape and a rough diagram of an airplane on a napkin and gives a brief explanation of it.

Amy judges that the correct amount of time has passed, and checks the mirror. It is charged.

"Hey guys! It worked!" she announces.