"Set to go. Unless we want to do any more research before we do, ethernet's hard to come by on the road."

"If you can't think of anything in particular to look up, I can probably pick up just as much background information on the world from talking to you as I could from the ethernet."

"Fair enough." A carriage is called. "I'm surprised we don't have a standard summary for extraplanar visitors, actually."

"Do you get many?"

"Concept's not unheard of, though usually they're from worlds that run on the same fundamental principles as ours? I have never heard of anyone who needed an explanation about experimenting. Summoning's sort of different circumstances, there are accidents but mostly within the local set of planes..."

"I wonder why your neighborhood all has this property. ...I hope it's not contagious."

"...yeah.

If practically nothing stretches to adjacent dimensions then I can't see why that would be the exception. ...though you did say we're adjacent to the unusually evil Arda?"

"You are. Science works there as normal. We don't know how adjacency is established or how worlds start, though, it may be that the unscience worlds are all clustering together after... deciding to be anti-science... for some reason..."

"I mean, the reason's pretty clear. The universe is aware when it's being poked and resents it. It's shy. As you like. The accidents that you get if you try sophisticatedly dangerous stuff is consistent with someone pulling the strings who hates it when people do that. So unless universes that aren't sentient or don't mind can become ones that are and do..."

"I guess. The Ardas are all run by this mostly noninterventionist metadeity but he seems okay with what we get up to, so far... no sign of anybody running the show elsewhere."

"Lucky you. ...though tons of worlds turning out weirdly similar suggests someone running the show, no? Maybe people have a more sophisticated way of thinking about this in worlds where you can do science."

"There are limitations on doing science like 'can we fiddle with any of the dials and see what happens' and we don't know how to manufacture worlds, affect adjacency in any way, etcetera, so we haven't gotten anywhere on that."

"Huh. Well, I hope we're not contagious. Any examples of worlds changing adjacency?"

"No - and the Tesseract was extremely disgruntled to learn there were worlds it couldn't reach, which suggests Edda has not had any new neighbors or lost any old ones in its lifetime, which is very long."

"I think that's good news, right? More regularities means more you can count on being able to do."

"Pretty much, yes, we don't have to worry about anybody losing an adjacency and being unable to get to the rest of us, say."

"And this is the first world you've hopped into that broke your stuff?"

"Yeah. I mean, Gem had a bit of a scare when she left the Wish neighborhood and her wish thing didn't work, but nothing else spontaneously failed, this is the worst case of that."

"Our apologies for having such an inconvenient world!"

"I don't think it's your fault."

"I mean no, not personally? Still sucks. 

So what makes a world an Earth or an Arda, same geography? Same people?"

"And same history. Ardas all have the same set of Valar making the same set of stupid decisions, Earths all have the same set of countries and series of wars and so on."

"And we usually show up on Ardas?"

"Except for here and Hex, all instances of your family are Arda natives, yes."

"And same personalities and everything?"