Downstairs the door opens and in walks a six year old girl with a weird animal.
She will encounter some slightly older kids without animals. "Oh, new person! Welcome to Milliways!"
"I think they were meaning to write up a fact sheet but never got around to it? Anyway! There are other dimensions! Some have magic, some don't, some have humans, some don't - I'm assuming you're human, you look human -"
"I look human 'cause I am, this looks like a Zigzagoon 'cause he is..."
"We do not have Zigzagoons. Anyway, Milliways randomly opens its door on new worlds - or, not randomly but we aren't the ones controlling it - and people are hanging out here curing everything wrong with all the worlds we can reach - like, if you have death, we can fix that -"
"Close the door. Pauses time in your world so no one dies while we're explaining. Maybe get a grownup first if you know one who's close by and would be useful?"
She shuts the door. "Useful for what? Most grownups aren't particularly."
"Fixing your world? I mostly know useful grownups but Milliways seems to mostly grab useful people. Anyway, there's a kind of magic being you can summon and if you do that then you become one when you die and they're indestructible and live forever, so that's death solved."
"Uh, you're supposed to trade them stuff when you summon them and some places don't really have anything to offer them, and if you do something stupid then they can get loose and kill people - most of them don't want to, but if all humans had tons of magic and were indestructible and wouldn't get in trouble for it..."
"Well, do they like Zigzagoons, we have a lot of those."
"And you're the only ones who do, so I bet Zigzagoons will go over great unless feeding them and taking care of them is a hassle or something."
"Magic food or anything? What happens if you don't train them?"
"Nnnno, regular chow and treats are fine. If you don't train them then they might do things you do not want them to like eat your furniture or something."
"Those don't sound like dealbreakers. Yeah, you can trade Zigzagoons. Are most people literate?"
"Lots of places they aren't, my world they aren't. We still do summoning in those but the Elves send tons of support staff. Wanna go summon an angel?"
"There are kind of a ton of things, do you have specific questions?"
"Do I have to trade something right away? I want this Zigzagoon, he's mine. I'd have to go catch another one."
"You're supposed to trade stuff every time but I'm a wizard, I can give you something for it this time."
"Where I'm from some people have magic. We can use it to make stuff, and daeva aren't magic so we can usually trade them magic stuff. If they want something mundane we can buy it off the bar."