"We should probably start drawing up blueprints, this would be way easier to talk about if we had blueprints..."
Cam finds a table in Spring's house and puts a large piece of paper and enough (blue-leaded) pencils for everybody on it.
Prime is helpful enough to draw out the current portal room, and starts adding necessary adjustments to it for expansion. He's practiced in this kind of thing, after all. He's made his fair share of portal hubs.
"A mini-medical bay would be great, too, with harrowing experiences and all. Should I start working on that, I think I have the most experience, but I might be wrong..."
"I can stock it with some basic magical herb mixes. Spring knows her stuff, but at a lower tech level - though she both lives here and can insta-heal infectious diseases by poking people."
"I have notes at home, but -" She looks at Cam. "... Sweeeetie. Will you re-make me my notes? Please?"
And then she starts muttering things about where to put what medical equipment and how diseases and pestilence won't be a problem with Spring but whether or not it's worth the space given up to have backups just in case she's not present. She also starts drawing out a basic floorplan of the medical bay on a mostly empty page of her notes.
Temperature regulation's handled by Ice, negating the need to keep the entire place enclosed, so they don't. They don't open the entire mountain up, but they do want it to be pretty easy to leave, too, so various exits to the outside world are made. Adana does some fiddling with the content of the mountain in order to keep the entire thing from collapsing in on itself, but she hides the high-tech, strong, super tough, not-actually-nice-to-look-at alloy behind more aesthetically pleasing rock mosaics.
Electrical wiring is completed throughout the entire place, with a very large generator situated neatly by the base of the mountain. Water filtration is handled similarly. With the difference in technology levels, Cam has to add a method to convert power and there are two types of outlet instead of just the one - one for Cam and Adana's level of technology, and one for everyone from twenty-first century Earth. It's likely they'll have to add more, but since they don't actually know what those are yet, they can't do anything more to compensate for them except leave lots of room in the wiring and space in the walls.
Along with the meeting room, medical bay, apartments, library and computer lab, various conveniently located bathrooms, portal hub, and secret passages to various important places and exits and entrances out of the mountain, they add a room specified for Ice's rituals. It gets two carved diagrams into the floor - one for resurrection (the updated version that works on mages properly) and one for granting immortality. There's another large, blank space for other rituals, and an absurdly large pantry filled with dried and neatly labeled herbs for use.
Another addition is one that isn't actually working yet - Prime and Cypress are very, very insistent that a mirror network with more than two mirrors attached to each other is impossible, but they would both very much like a technological solution to this problem. Unfortunately, no one present has the know-how to actually manage it. Yet. Adana promises sincerely to work on it, she's been itching to learn about technology eventually anyway, and is pretty happy to spend her time studying that. Until then, they have the space set aside with plenty of room for the angel to work in.
Less importantly, but for the sake of fun, they add a giant recreation room of doom. It gets equipped with a large television, various video game consoles (complete with games) and a neatly organized movie and television show collection. Hilariously enough, they are probably not going to use this very often, but having it around seems like a good idea in case of traumatized, harrowed alts. Or possibly just for when someone is bored. Either one.
For the sake of placating the neighboring gods, they also put a shrine to each in the compound. One on Rae's side, one on Perinixu's. It's probable they both will get little use, but both gods will appreciate having little shrines dedicated to them anyway.
When pressured for an opinion of the place, Zevs ask for a sparring ring, which is provided. The Zevs are extremely excited about this. They (well, Zane, but the other Zevs help with ideas) fill it with lots of weapons and gleefully start trying them on each other. Non-lethally, thankfully.
And then, they have a portal hub and base of operations.
Cam makes it appear in a tilted position; it swings and chimes a few times until it settles down.
Adana giggles at this, and flies over to kiss her boyfriend for a job well done. Teamwork!
"You know, we could move in here," he points out to her. "Since if we go back where we were living yesterday we have accessibility problems and I am disinclined to move in with your dad. We can still visit our world whenever and in our spare time not be shot at for being loose daeva."
"Ooo. Sure! I need to work on the mirror thing anyway, so I'll be hanging around here a lot. Might as well live here. Want to grab one of the provided apartments, or go make our own house somewhere?"
"Detached house, I think, these are designed for nondaeva and have, like... kitchen cupboards."
"Ah yes. Kitchen cupboards. The bane of demons everywhere," she snickers. "Yeah, sure, let's go build a house."
"Spring!" calls Cam. "You don't mind if we park a house on your mountain, do you?"
"Go ahead. Come fix my house too, and see if Idania wants to wheedle you into doing hers, while you're at it."
"I have no idea who that is, but we can go find her and renovate her house, along with yours. I'm pretty fine with being Cam's architecture buddy."
"Idania's my friend, she ushered me into this world from my original. She's Rae's acolyte. And also lives on this mountain." Out they go, as other Bells and Adarins and Zevs return to their respective homes.
"Aha. And she, unlike just about everyone else I've met, is not an alt of myself, my brother, or my boyfriend?"
"Right. If there are more of her we haven't found any yet. Idania, you home?" calls Spring when they're near the relevant house.