This is not a treehouse bathroom. It does, actually, have a recognizable restroom sign, over there?

Bonesaw almost turns off her bladder, before deciding that a bathroom is probably a good way to have an excuse to look around a place without answering questions.

The bathroom is alarmingly normal. Porcelain toilets. Tile floor. Bright ceiling lights. Mirrors and sinks and stalls. Pink liquid hand soap. No-touch paper towel dispenser.

Bonesaw's hair is dyed bellybutton blue so hopefully no one will recognize her but... oh her hands are not exactly in a good state for her not being recognized. She washes them.

She missed pink soap. 

The pink soap is completely normal and does a normal job of washing her hands.

When she emerges from the bathroom the floor goes from tile to wood, and there's a window full of exploding stars next to the row of padded leather booths and their tables, and there's an unstocked unstaffed bar with stools,

- with one guy sitting at it, drinking a mug of coffee.

Bonesaw is confused.

"Your wings are really pretty but also muscles don't seem like enough to make them work very well."

"Oh, uh, yeah, they wouldn't work great on humans. I can't get too tired."

"How?"

"I'm indestructible. That includes that I can't get too tired, if I don't want to, it just stops at a certain point of progression."

"Oh I had a friend like that."

"Oh?"

"Yeah, she wasn't blue though."

"That's an individual fashion decision."

"Like my hair."

"Like your hair, yes."

"How did you get here?" 

"Walked through a door and this was here instead of what's usually on the other side."

"Oh that's also what happened to me."

"I think it is the standard means of accessing the place. - the bar is a person, she writes on napkins to communicate."

"What sort of places do people come from?"

"Dunno, you're the first other person who's walked in since I've been here, I've just been talking to Bar some."

"By writing notes?"

"She can hear, she just writes in response."

"Oh huh, that's neat. Does she also serve drinks?"

"Yes, though only the first one is free so if you want to be here for a while and don't have money I can make you stuff to eat, I can make stuff."

"They don't really have money where I came from, what sort of stuff do you make?"

"Not antimatter."

"Can you make living things?"

"Yes but they come out stupid, if they were supposed to be brighter than a snail."

"You can't make neurons?"

"The neurons are there but do not work as they would be expected to. We don't know why."

"We?"

"My species, demons."

"Oh!" So not from her home.

"Can you make me a brain to look at?"

"...why?"

"So I can find out why it doesn't work."

"...what, are you a neuroscientist?"

"Sort of."

"Any chance you would cause it to... work? Because that seems like it might have ramifications."

"Yes."

"I don't think I know you well enough to embark on such ramifications together."

"Oh.... that's probably smart."

"Yeah, I think so."

"...I do bet I could have fixed them."

"I can think of situations where that could be useful, admittedly, but none I want to start experimenting with right here right now."

"What sort of situations?"

"Well, if I create the brain of someone who's died, maybe it has all the information on it and it just doesn't operate correctly, and if it could be made to do so they'd just be alive again, that would be neat."

"-you can create people who already existed?"

"...yes?"

"If there's someone specific -"

Nod.

"Who, and do you want just the brain or the whole thing?"

"My old mom. Her... all of her. And Glaurung. And also my dad. And my brother. And my dog."

"Maybe not all of Glaurung actually."

"Not... all of... Glaurung?"

"He wouldn't fit in this room."

"...ah. I maybe need more information than I had guessed before I start making you people."

"Glaurung was a growing dragon."

"There's a back yard, I guess, though I don't know what you'd do with him afterwards if it worked."

"Oh if you make just his brain I'd fit it into a smaller body so I could lift him like he wanted."

"What exactly is it that you... do."

"Art? With bodies and stuff. Like a doctor except I'm better than normal doctors."

"I went to medical school and do not consider medicine among the arts."

"Well lots of people are wrong about that."

"...you're welcome to explain how."

"... most people don't like it when I try to explain how." Except for Beka and Jack and Sauron and the Nine.

"...I... see. How, uh, old are you?"

"Thirteen now."

"I think I might have to hear some explanations I will not like in order to get to a point of being willing to supply you with brains."

"... You said your being blue was a fashion choice?"

"Yeah, I made the wings and tail out of designs in a catalog and picked the pigment in the process."

"Oh neat! How'd you get it set up?"

"...set up? No, I just," he materializes a Koosh ball and tosses it to her underhand, "made them."

'Woah that's really cool! I don't think one ever met anyone who could make their own biology! Oh unless you count Spree but he could only make more of himself which is boring since he's boring."

"There's billions of us. We make stuff. The design step is harder, hence the catalog."

"Oooh, if I make you a design that's really hard for me to make on my own could you make me it?"

"...I could, if it's not, like, magic, or anything..."

"Well there are lots of interesting things that aren't magic..."

"If you want dinner and don't wanna pay Bar I can make you dinner but I'm kind of concerned about what interests you."

"I can get dinner from my home."

"If you let the door close behind you once you're back in your own world, you're out of Milliways till you get another door, which might or might not happen."