"Hmm. Could probably clean that up without too much trouble, but maybe not in here."

"It'd risk flooding, if I deliberately allow the overcast to go through."

"On what scale, though?"

"I don't know, I haven't tried it!"

"Do you have a guess between 'do the experiment in a room with nothing we'd be sorry to lose', 'do the experiment in a house we wouldn't be sorry to lose', and 'take a trip to the beach'?'"

"I don't know! I don't have accurate results on this because other people always cast in non-native languages and when I overcast there's always the confounding factor."

"I suppose that makes sense. Inconvenient for figuring out which spell to try, though. Possibly the conclusion is that properly cautious precautions for anything other than invisibility will take longer to set up than the invisibility will to run past its allotted time."

"Likely. I could make something else besides me invisible."

"That'd be less inconvenient. Oh, by the way, I want to verify something—"

He conjures a handful of glittering gemstones, in assorted shapes and colours, and holds them out to her.

"Can you try - doing the suppression thing at those? I want to see if the ones that are properly conjured count as still magic enough to destroy. They shouldn't, but it'd be interesting and potentially useful if they did."

"Uh, sure." She reaches out for one, wishing that it not exist.

That one vanishes!

But when she's tried them all, two out of the five remain.

"Well, you won't be able to singlehandedly knock down the palace," he concludes.

"Hm. I don't think it makes a difference but just in case -" Reaching hand goes clawed. It makes no difference. "Mkay." She returns it to handedness.

"And now we have these conveniently useless objects for you to experimentally turn invisible!" he says, offering her a diamond the size of a grape.

"I guess you don't have scarcity making them valuable, huh." She flips to the invisibility section and casts an overpowered spell in English. The diamond vanishes and she sets it down. "I can try the other one in this language to see if it's more like English or more like French."

He hands her the second gem, an equally enormous sapphire.

"They are kind of scarce overall, actually, because true conjuration is not a very common talent and most people who can do it have better things to do than pour gemstones into buckets all day. But since it's a talent I happen to have, they're not meaningfully scarce to me."

"Makes sense." She flips to another spell and translates her incantation into, "Be unseen, let light pass unaltered through you, invisible to every eye and sensor." And then she draws over the used spells again.

"The vague hints about the principles of this magic are fascinating," he comments.

"It's a pretty neat system. I'm lucky I landed with my backpack or I'd be stuck with the runes I can draw from memory, which I can get things done with alone but nobody else could."

"Where do new runes come from?"

"If you have a bunch that all share a meaning, you can derive new ones from them, but I don't know where the first ones came from."

"Really? How's that work?"

"There's this intolerably complicated deterministic process for how you can draw them all out in a ring around a blank center space and make marks in the middle according to what's on the outside. This means you can get different results depending on what position and permutation the ones in the ring are, and that there are thousands of runes that have any given meaning, though they'll vary widely in how much of it they have. My rune dictionary only has five thousand runes total, which is plenty for most purposes, but sometimes if I want to make a spell really elegant I'll derive a few to see if any of them are convenient or fit more neatly into a diagram."

"Wow. Now I kind of have an urge to spend a week sitting around deriving runes."

"It gets old! But I've done it a lot to make sure I remembered the process - dictionaries are weirdly scarce, I wanted to be sure I'd be okay if mine were lost or damaged, so I did my best to memorize the process in addition to copying out most of the contents of the book onto a computer."

"Huh. Weirdly scarce like how? Is there a known reason...?"