"...But it's not the same, right? Because I can't learn to control qi, if I'm starting at the age I am now." Although Merrin does still definitely want to test that theory. "...Also what do you mean by people not learning it because it's 'evil'? Does it - cause harm? I...wouldn't've thought that it could cause harm to the corpses or - ghosts - ....um actually it's occurring to me that I don't think I really understand what you mean by ghosts and that seems like another thing that doesn't exist in my world but is really relevant here, can you explain?" 

"If people have unfinished business or are really full of hate or anger or resentment when they die then they'll stick around and try to accomplish whatever they were doing when they were alive. I am going to be one hell of a ghost."

What???????????????????????? 

- Merrin listens to the part of her that is not so much internally screaming as just internally making quiet incoherent noises of upset confusion and indignation, and acknowledges that yes this is a very reasonable response, and then tries to set it aside and rewind and go over the sentence that was just said again in her auditory memory loop.

Nope, she is not making any more progress at having a reaction more useful or coherent than what??????

(Externally she still looks calm, mostly, but if either of the boys is paying attention they will notice that her expression has gone rather fixed and she appears to be holding her breath.) 

Eventually she remembers to breathe. 

".....On further reflection," she says, tonelessly, "I - should clarify what happens to people when they die if they don't, um, have enough resentment or unfinished business to be ghosts. I don't mean to their bodies, I - um, I had been assuming the dead bodies there were just bodies, not - minds - not still sentient with the original personality... That's the part that I, I, want to know, what happens to..." 

"The soul reincarnates into a new body? Do you not know that in dath ilan."

"The what does what? ....No. We do not know that in dath ilan. I'm - not sure that's a thing in dath ilan - if it were observable in any way then someone would have noticed!" She takes a shuddering breath. "We freeze people. To - try to preserve enough of their brains, the structure, that we can bring back - the key parts that are them, someday..." 

"...no, I don't think that would work... you would still have the memories but the soul wouldn't be there-- can I have a pen?"

Merrin doesn't have a pen, and glances over sort of hopefully at Wen Ning, but she is mostly distracted by the fact that what and how and but that isn't how anything– 

"- I think maybe there's a translation problem here? You're saying - a word, I can tell it's a word of one syllable in your language, but to me it's coming across as...I don't know, 'continuous-directed-continuity-of-experience' - assuming that translates to anything to you. And that's all in the brain? It's measurably all in the brain. Obviously someone's memories aren't the only - important thing about their existence, aren't the only thing that makes up their mind-state - but we know that things like, I don't know, how much someone tends toward being patient and kind versus impulsive and angry are in the brain, because a sufficiently unlucky injury can change that - or it can make you not able to name objects, or specifically not able to recognize and name objects by touch, those are all in the brain, and we know that, and I genuinely do not see how there's any unexplained empty spot left that would be a soul. I mean, I don't totally understand how the physical structure and encoded patterns in the brain produce the phenomenology of conscious experience, but I also don't understand the math we use to build bridges that don't fall down. I am still very very sure that - actually the answer to this question is knowable, and our Civilization knows it, and the answer is that all of the traits that make a person that we - know how to name and measure or even just to care about - are represented by something in a person's brain. And so I'm very confused about what a soul could possibly be if it's something you couldn't recapture if you could actually retrieve all the information that had been in someone's brain." 

"Right, but for us it's obviously and measurably not in the brain. I can take a soul and put it in a spirit-trapping pouch and carry it around with me, and I know I have it because I can sense its presence and experience its memories with Empathy, and the fierce corpses out there have their brains all intact-- well, most of them-- but they don't have souls so they're puppets I can do as I like with."

"You can just trap the - disembodied representation of the continuous-directed-graph of an entire person, in a pouch? And then interact with it?" Merrin is staring at him with a level of incredulity appropriate to his having just proposed that two plus two equals five if you're doing a headstand at the time. 

(...it's not actually as modelbreaking as math not working the way she expects, it's - possible to imagine a set of physical laws that results in cultivator magic and souls and puppetable corpses, but Merrin is kind of running out of space in her head for bizarre startling revelations that are going to require her to refactor all of her beliefs and anticipations about the reality she is currently in. Because she can't do that right now. Possibly she isn't going to be able to do that at all, and will instead be doomed to spend the rest of her existence here in a state of constant background confusion because she no longer has all of Civilization behind her, building and studying and understanding the world and then figuring out, piece by piece, how to teach that to children. Even children like her.) 

"I assume that in the Americas or Europe or Africa or wherever you're from souls also work like that, you just don't have high enough cultivation to do it properly. I mean, have you ever woken up a frozen person to check whether they still have all of their personality."

"...We're not actually certain that that works in practice. Because we haven't checked. I just - would be really, really, very surprised if our world had physical laws where cultivation could work, or where it was possible to puppet dead bodies around, or where you could put mindstates in a pouch and sense their memories - because dath ilan is full of people who are much cleverer than I am and studying things very hard, and I'm pretty sure that has ever included meditation and martial arts and whatever the other things were because there are a lot of people - and I think someone would've noticed. At the very least someone would've noticed that there was some tiny inkling of confusion, and then a lot more people would be all over that." 

"But we know physical laws are the same everywhere in the world because people have been to everywhere in the world and they haven't found anywhere that their swords stop working."

"...I think that's by itself pretty strong evidence that I'm not from this world? I've been assuming I'm not. Mostly because - um, if 'world' is actually translating the way I've been assuming, your world is - a planet, that has continents and ocean, and when you're guessing where I could be from you're talking about different continents on the other side of oceans? And we know what's on every single landmass in dath ilan. There are...literally any groups that aren't in significant contact with the rest of Civilization, I guess, but they're tiny, and there's no way a massive conflict like this one would go unnoticed and un-intervened-in. There aren't any unmapped areas that could possibly correspond to here. When I - died, or whatever happened - I was on a plane, which apparently translates as 'very large sword' in your language or something but it's...more like an enormous metal building that can propel itself through the air, and move hundreds of people across the oceans between continents. If you've never seen planes flying overhead - they leave sort of cloud-trails in the sky - then I think that is also a pretty strong piece of evidence that we are not in fact from the same world." 

"Whoa!"

"Ningning! Paper and pen! Merrin, draw me a plane and tell me how it works."

Oh. Okay? Sure? This is what they're doing now? 

...Well, it may not seem like the top priority to Merrin, but at least Wei Wuxian is cheerful and listening to her and not getting so angry about all of the incredibly horrible events in his past, and the people (apparently, somehow) responsible for them, that it starts causing medical problems.

(And, if she's honest with herself, which seems like an important goal to aim for especially now, it's helpful for her as well to have a distraction. Something concrete to focus on, that does not involve refactoring her entire worldview. Or thinking about dead people who she wasn't there to even try to save.) 

...Merrin is okay at drawing, but the light is poor and the writing implement is unfamiliar. She does her best.

"What's an aerodynamics?"

What a good and reasonable question! Merrin...is going to have to make some significant effort to answer it, even though she has all the prerequisite background knowledge, because 'while half of her cognition is going toward tracking her patient's medical status' is not really the ideal circumstances to dig up and retrieve science lessons from a decade ago! 

"Um. In short it's the physics - the math and physical laws that cause and predict - how things move in air. Which is a fluid, like water, so it's a subset of fluid mechanics - I don't know if your world's scholars know that air can be modeled as a fluid? I think it's less obvious than it is for water, because air is much less - thick. Anyway. You can also use aerodynamics to model how birds fly - or how bees fly, which is actually pretty different - but the really short version of how planes fly is that the wings are shaped so that if there's thrust, a force pushing the plane forward - which comes from the engines, there - then the air flows around the wing shape in a way that creates lift, which is an upward force." 

....damn it she totally knew this at one point, it's not even counterintuitive, but what - 

"- I think the way it works is that the wings are shaped to be flatter on the underside and rounder on the top, which means air flows faster on the top, and that creates a pressure difference - air pressure is basically the density of air, you can imagine it like the air on the top side being stretched as it flows faster, sort of - and then that causes an upward force. .....I could probably explain it better than that with the actual math but I'd need more paper. And more time to think. It's been years since I studied this. - Um, also I'm pretty sure there are some moveable components on the wings that can change the wing-shape and thus the aerodynamics of the plane, but to be honest I probably just won't remember the details there. It's - probably the sort of thing you could re-derive with a not-too-complicated set of experiments? If you wanted to build planes here." 

Wei Wuxian is scribbling down notes into his notebook. 

"I want to build planes!!!"

"Wait, if your world knows this it knows lots of things."

"I'm very nauseous and I'm cramping."

It sounds like her world knows SO MANY things that are apparently unheard-of here, and Merrin is - suddenly looking forward to the point in the future when it will make sense for her to help them build planes. Even if it requires dredging half-forgotten math up from the cobwebby basement of her brain. 

(Probably that will be a lot easier at a point when she is not mostly occupied by her patient looking worryingly sick in front of her.) 

"....Yeah, that makes sense. I think you should lie down again and hold still and try to relax, and that will help. I can make you more of the herb mix for nausea, and I could maybe put sugar in so it'll taste better?" 

"I think that I should be treated with more facts about physics."

(Wen Ning is cracking up.)

Honestly, this aspect of Wei Wuxian's personality is much more likable! 

"...Okay, I can tell you more facts about physics but you should also lie down. Maybe you can get Wen Ning to take notes for you? ...What sorts of physics questions do you have. Um, does your world know anything about optics and how eyes work? I think I can do a pretty good job of explaining that. But I'm not going to unless you lie down and relax."