"Oh. Uh, do you think I can probably visit your world again in a few years? Would you mind showing someone who can go between worlds the way there?"

"We don't have bus stops set up yet but once there's a route you'll be able to get there, now and in a few years too!"

"You use buses? To go between worlds? Why don't you just teleport?"

"Not everyone can teleport, so instead we have bus drivers who can teleport, and they teleport the buses. The physical bus is just to make sure they know who's coming along and who's not."

"Oh, that makes sense. I guess if you need things to put people in and have buses lying around."

"I'm not sure they were exactly lying around, but yeah."

Nod. "I imagine my king and her council will be interested in hearing about mass transit in your worlds, we haven't had the necessary technology or magic for long."

"On a single planet I think the buses usually fly, instead."

His eyes go wide again. "That sounds fun. I thought, uh, that there was some reason buses use wheels even if you can fly? But I only know so much."

"I think flying costs more fuel and you need better drivers or programs doing the driving?"

"Programs?"

"Oh, they're a thing that makes a lot of fancy machines work right. I don't know how much you want to hear about it right this second."

"I'm interested!"

"My computer is this thing." She pulls out her tablet; it's ruggedized so it doesn't splinter to bits when handled with her sharps. "It does lots of stuff - I mostly use it for sending messages to other envoys who aren't right next to me at the time but it'd also, like, play music, or tell me where the best-reviewed restaurant that serves tree bark in a particular town is. It kind of does all those things by doing math. So, programmers, people who write programs, are professionals at turning all kinds of random tasks like 'play music' or 'fly a bus' into math, so that computers, which can only do math, can do them. And then you can make machines that use that math to turn bits of a bus on or up or to the left or whatever, whenever they need to be different, so nobody has to personally pilot a bus, you can just make a million copies of the math problem easily as soon as it's been done once."

"...Huh. I don't think I really get it. Uh, by a restaurant that serves tree bark do you mean someplace really expensive or do you mean something else?"

"Oh, I mean I literally eat tree bark. Though it's very unusual for restaurants to carry it in areas where my species isn't common."

"So do we if we can get it but it's not cheap - I mean not just any tree bark, there's one kind that humans eat. But not by itself, just ground up and added to other things."

"Is it cinnamon? I like cinnamon but it does have a pretty intense flavor, my favorite tree bark is maple."

"Yeah. I haven't tasted maple, I don't know if I can eat that one. I haven't heard of anyone else trying it."

"I think humans like maple sap, usually, not the bark."

"Huh, efficient! Hey, if there are all these kinds of people I never heard of, are there kinds of plants, too?"

"Yeah! The plants on this planet are mostly a lot like the ones on planets humans usually come from, but there are other kinds of planets with their own plants. And some of them you can eat."

"Interesting... and human worlds are common, aren't they? Not just that there are a lot but that if you pick a random world..."

"Yeah. Earths are very common, and then on top of that there are not-Earths like this with humans on them anyway. It's weird and we don't know why it's like that."

"And things tend to be all different or not different at all? Like there aren't worlds with more of you and no humans but with cinnamon and foxes and lentils?"