He feels an open summons and lets it grab him -
"I mean not why did you think it was wise to obtain a demon, I mean why did you think it was possible."
"And knowing you, you'd duck out of the work somehow even if you were possessed," snorts Ripper.
"...Okay, I don't think you did time travel, I think you pulled me from an alternate multiverse."
"The important thing," says Rayne, "is will you clean—" Ripper elbows him in the ribs. "What?"
"We just accidentally summoned an unknown kind of demon from an unknown universe," says Ripper, "the state of our floor is not our biggest problem anymore, will you give it a rest."
"So, tell me about this place. Like I'm from outer space, because I can tell you're speaking British English and can guess you're counting years from the supposed birth of Christ and you apparently play something I can identify as a guitar, but I'm not sure what depth of similarity that implies."
"I'm not," says Rayne. "What do you want to know about? Magic?"
"What do you know about magic," says Ripper.
"More than you do."
Ripper picks up the not-quite-useless demon summoning text and throws it at him, not very hard. It bounces off his arm.
"The basics of magic, and just for completeness can you - I don't know, list the continents and name random extremely famous people and things in case I don't recognize them all? If you're thorough I might even neaten the apartment some, although I draw the line at interacting with anything you may have puked on."
"We haven't puked on anything," says Ripper. "We're not that kind of drunk."
"I don't think the nice demon needs to know what kind of drunk we are, Ripper. Famous people and things..."
"Hey, is Australia a continent?"
"Ha, you missed one."
"Okay, so standard continents. I'm just going to start - listing things. Revolutionary War. The Mandarin dialect of Chinese. High heeled shoes. Daffodils. QWERTY keyboard layouts. The film 'Jurassic Park'. Icebergs. Do all of those things sound like things that are?"
"Name another famous person."
"Name one who's not a musician and not dead."
"Oh, fuck off."
"Okay. And on top of your Earth stuff you have kinds of demons who are not my kind of demon and magic that is not my kind of magic?"
"We have more kinds of demons than we can count," says Rayne. "More than a few kinds of magic, for that matter. And gods, do you have gods? Gods are a nuisance."
"We don't have gods. We have demons and angels and fairies."
"And fairies?" says Ripper.
"That's what I said, yes. And humans can do little tidbits of magic aside from summoning us - the catchall term is daeva - but most of the heavy lifting is summonses."
"Yeah, that's pretty much nothing like this universe at all," says Ripper.
"So, tell me about this universe," sighs Cam, "please?"
"See, you're not too drunk to explain it after all," says Rayne.
"Can non-humans use it?" Cam asks, gesturing at himself.
"Want to learn some magic?" says Rayne.
"Don't teach magic to the demon," says Ripper.
"But Ripper, you always help me with my bad ideas," says Rayne, batting his eyelashes.
"Why does it seem like a bad idea, though?"
"Well, I know you're not one of our kinds of demon, probably, but I don't know what kind of demon you are, and most of the kinds of demon I know about are bad enough with the magic they can already do."
"I can make arbitrary nonmagical matter. If wanted to suck the entire planet into a black hole, it would already be done. My knowhow is not the limiting factor on how bad I can get, but it might be the limiting factor on how much useful stuff I can accomplish while I'm here."