This door was supposed to lead to the hall closet with the cleaning supplies, but Bella doesn't see any good way to mop up spilled soup from the kitchen floor. "Extraplanar studies students," she mutters, stomping into the bar in her nice useful boots. If she takes notes on this place she can probably get extra credit somewhere for it. She goes up to the bar, and notes the lack of bartender. Maybe they stepped out for a minute.
"Or another plane, my first guess about the bar was extraplanar studies students goofing off."
"Well - come on, 'other planet', talk about bad science fiction - planes are - do you not know about planes?"
"Ugh, I can't remember the textbook, so - don't quote me, but a plane is another existence in which the laws of magic differ in some ways and which can usually be accessed only by magic."
"Oh," says Parvati. "I don't know whether to be irritated or afraid or fascinated, honestly. You mentioned subtle arts, is that the sort of magic you do?"
"Magic-detecting spells don't detect it. Divine and arcane magic have intercompatibility that subtle arts doesn't have with either."
"That makes sense." And opens up a lot more questions. But there's one she should ask first. Taking a deep breath, and crossing her fingers that the answer won't be yes, she asks, "Is any of your magic transferable? Could someone from my plane learn it?"
"You have to be born with subtle arts, although there's some debate if you can get from 'no potential' to 'some potential' or just from 'no discernible potential' to 'discernible potential'. At home anybody can pick up magic if they're smart enough, but I don't know if your plane will allow it."
"Oh, thank you," she says, smiling. Magic is much more fun when she can just study it, instead of feeling obligated to use it. "Would you be willing to tell me more? I'm afraid I've been terribly rude, peppering you with questions...oh, would you like a coffee? This is a bar, after all, and I think I have some money." She starts rooting around in the pockets of her jeans.
"I don't m-" She blinks at the napkin. "Oh, huh, lucky us. I usually avoid coffee, though, it messes with my sleep patterns. Uh, hot chocolate?" She addresses this to the bar as though that's only a mildly odd thing to do and receives a large mug of hot chocolate. With marshmallows. "Thanks."
"Iced coffee, please. What sorts of things do subtle artists do? How much potential did you have?" She does a double take at the napkin. "Oh, is this bar run by some sort of computer? Or an invisible person?" She waves politely at the potential invisible alien.
"Subtle artists do mental perception and interaction, and some of us can also do telekinesis or pyrokinesis. I'm well above average for people with perceptible talent but hardly top percentile."
"Oh, congratulations on being above average. Can you do pyrokinesis? I do hydrokinesis, so that would be rather ironic." She notices the napkin. "Erm, thank you? Are you alive?" (This is hardly fair, she can barely talk to humans, how is she supposed to know what to say to a bar?)
I am a person, but not in the classical sense 'alive', says the bar.
"Teek...oh! Oh, telekinesis, it's an abbreviation. That must be quite helpful for everyday tasks." Her cat, meanwhile, is winding his way around her legs in a desperate plea for attention. She picks him up and places him on a barstool, then addresses the bar again. "So, if you're a person, could you please tell me just how you managed to appear outside my living room?"
The door leads to any door based on patterns or whims to which I am not privy. When you each open it, it will lead back to your respective worlds.
"I suppose it would be difficult. I can sympathize. It took Lord-knows-how-many hours of work to get my powers to do anything useful. At least you have professors who know what they're doing." Parvati may be a little jealous. "If you weren't a subtle artist, what other types of magic would you want to learn?"
"Arcane, probably. I can never bring myself to be very - positively interested in gods or nature, so that's the major divine magic out."
"How do you manage that, if you don't mind me asking?" she asks the bar. Her cat meows. "And does the 'first drink is free' rule apply only to people, or could I get my cat a treat?" She turns to Bella.
"Would you mind telling me more about arcane magic? And also...gods, plural?"
"I only know like high school level arcana," says Bella. "And that was a while ago. Do you only have one god active on your plane?"