"—the 'boffins,' you keep using that word..."

"Oh, heh, it's a common slang for inventors and scholars from London University."

"Alright I guess." She finishes picking her stuff up and says, "Ready to see the light of day again?"

"How fast can you fly, Kaede? And Vasil? Run?"

"Depends on how much mana I'm willing to spend."

"This unit can reach speeds of up to a hundred kilometres per hour."

"I can cruise along at that speed with a passenger easily, at least until my 'wing breaks down from lack of maintenance. So we'll make good progress."

"Oh, well, let's go, then. I left a magical trail that should light up if I poke it, but I guess you should be able to find it if you look."

"Sure. I should keep talking about the science stuff I know about before I forget it all... We might be able to remake some of it based off what I picked up, even if I'm no boffin. Vasil, you've probably got a pretty good memory I suspect?"

"This unit can safely store several thousand times the amount of information a human brain can without loss of accuracy."

"I don't think a human brain is meant as a storage thingy, really, but okay."

Pack up, pack up... "Hop on, Kaede." There's a second seat on her flying thing.

Hop!

And off they go, dodging and weaving at well less than her top speed up and put of these tunnels, following that magic trail.

She tries to articulate what she remembers about 'analytical engines' to Kaede and Vasil.

It sure does seem to describe Vasil pretty well huh.

"Hm... Sort of? But Vasil is impossibly complex. You'd take up a city at minimum if the boffins at London built you with what they know now."

"I bet they took decades to get Vasil and that was building on previous work."

"And we had to work with mere physics, not magic."

"Yeah I have no idea how you'd do that, a lot of the trickier stuff is much easier to do with magic than with anything else."

"A lot of clever folk trying a lot of clever, slightly desperate experiments, seems to be the gist of it."

Eventually they will reach a stretch of tunnel that goes strictly upwards until they emerge from a hole in the ground. It is mid-afternoon outside.

And what's the land nearby like? Barren desert, scrubland, coast...?

She has moved on to the major emerging concepts in medicine, which may not be new to Kaede's world but are pretty new to hers. Like washing one's hands. And vaccines.

Nope, they are totally news here and hoooooly shit she will need to tell everyone about that immediately.

(The land nearby is grasslands as far as the eye can see.)

"So an important thing for long term utility is not to overuse anti-biotics. Evolution will happen."

"Evolution...?"

"Er... This is one of the things they didn't explain so much as tell us about in school, but. The example they used was, say there are a hundred mice with brown and white spots. And a hawk comes and eats one every day. It can see whiter mice better than browner ones. So usually, the one it eats is the whitest. When the hawk moves away and the mice have children, there are more brown mice than white mice left, and they have more brown mice children, as a group. And this repeats until there aren't any white mice left. 'Germs' of germ theory do the same thing. If an anti-biotic kills most of them but not all, the ones it didn't kill, it won't work on when they multiply again later."