"They're machines that can fit a couple hundred people in them and then fly.  You don't get them yourself, you pay for a spot on one that's going to do that.  I've never booked one but it can't be that hard once you know how; some people do it all the time."  Phone phone here's a picture.

"...well, if I were trying to order you to fly I'm not sure sitting in that would count. - you may refrain from reciting Frankenstein."

"Oh, would have that trapped me later I'd learned more of it?"

"Might've. They don't expire."

"Woah."

"Or, well, it'd wear off if I forgot your name, but mortals don't live that long."

"I'm sorry."

"It's not your fault."

"The fact that I'm really weird and keep being insensitive is probably my fault."

"You're only the second mortal I've ever met, I don't know what you're supposed to be like."

"I think - generally more considerate and less accidentally poking people in their wounds.  Emotionally."

"Well, you know, it was most of my life, it's big, hard to miss."

"Okay.  Well, I'm still sorry."

"Thanks."

"I should explain the bathroom to you.  This one's kinda weird, in that most don't have two doors, at least in houses, but this one does: that one there connecting to my room and another one out in the hallway.  I'm the main one who uses it, but not the only one.  They do lock but you should mostly leave them unlocked when you're not using it.  But, uh, you can get water from there, and take a bath once you're well enough, and, yeah."

"Were you going to do some kind of water related research?"

"- Yes.  Do you know, if I had fed you some metal or a rock, would that have done anything?"

"It would not."

"Okay, it's probably safe, then - in towns I think they put fluor-something in the water because it's good for your teeth - or humans' teeth, at least - fluoride, I think?  But we're on well water, and we do add rocks to it in the water softener, I think, to kind of cancel out other rocks that are in it naturally, and I don't think there's anything else but - probably I should just ask my dad."

"...cancel out... the rocks...?"

"Rocks!  Humans need rocks to live.  Also metals.  But bits of them that are too small to see, mostly, and - I'm gonna look this up."  Phone.  Phoooooone.  Phone.  "Okay, it looks like, yeah, we put salt or something in our water and even though the result doesn't taste like saltwater I think there are still particles in there, they're just bonded to whatever more-annoying minerals were in there to begin with."

"...I think that is probably fine? Drinking saltwater is not dangerous in this way for us."

"Even though we're adding it on purpose?"

"Right."

"...How bad is it to get this wrong?"