A napkin appears on the bar's surface.

Hello. Can I interest you in a beverage? First one's free.

It's in his alphabet.

"...and what does the second one cost?" he says to the napkin. Perhaps he's supposed to write it. Who even knows his alphabet? "Also, Quenya's banned. You'll get us both in trouble."

Reasonable currency-dependent prices, says a new napkin. I doubt very much this ban extends to the local jurisdiction and at any rate am not in direct control of the translation effect.

"...right. Okay." Curufin would be curious. Celegorm is - well, he's not not curious, but he's not going to run around taking samples and sketching and testing napkin capabilities, either. "Can you recommend me a drink?"

Of course. A glass of wine with a flower in it for some reason appears.

Well, in Valinor flowers were edible; perhaps in implausible bars they are too. He takes a sip. It's very nice. Is there an explanation for this place? Or do I have to discover it?

I'll be happy to answer your questions, although I don't know the answers to all of even the most frequently asked. The establishment is called Milliways, I am Bar, and the door here has temporarily co-opted the door you expected to be traveling through. When you exit it will most likely be the time at which you left and the place whence you came.

"Okay."

He glances at Huan. You want a drink?

I will have water.

"Huan'll have water."

A bowl of water appears.

And Celegorm sets it on the floor. "Guess my questions are - is this place safe? Can others find it? Who created it? Why did you borrow the door to my fortress? Could anything have left your bar and wandered into my city?"

It is quite safe here both by suspicious coincidence and by security personnel guaranteed to be able to handle whoever happens to be in the bar during their shift. Other people can and do find it, although people from your world will be inhibited in doing so while you are here because time is paused unless you hold the door open or something unusual is going on. Its origins are quite mysterious to me, and I do not control the door. Patrons who open the door by and large return to their own worlds; you could let someone in but it is improbable that anything would have entered your world via Milliways without that sort of assistance.

"Okay. Hi, security personnel. How does one get that job?"

One applies. Would you like an application?

"...you said it doesn't take any time back in my world? Yes, I think I would, though I'm guessing I can't fill it out in the alphabet you're using and I can't write very well in proper Quenya."

The time pausing feature is reasonably consistent. You may fill the application out in any alphabet you like or I can take a verbal interview.

Wanna apply for a job doing extradimensional bar security? You'd be most of the security.

Huan wags his tail. 

"Verbal interview'd be great."

So Bar inquires about what capabilities they would bring to bear, the availability of reliably nonlethal containment methods, situational assessment abilities, and their responses to seven bizarre practice situations involving unfamiliar species and magic.

"D'you need me to demonstrate that my dog is indestructible or will you just take our word for that? Or can you verify it? Anyhow-" and he answers.

I can discern his species characteristics, but 'indestructible' is a relative term, Bar napkins serenely. Suspicious coincidence will guarantee that you will not be on shift while any patrons enter the bar who can overwhelm him but you are not guaranteed to suffer no work-related injuries. Access to the infirmary is free, however.

"There's a prophecy about him. If intradimensional shenanigans can beat prophecies I need to immediately import bar patrons or something - or is there a rule against using the bar strategically like that? Anyway. Cool. We'll look forward to helping out whenever suspicious coincidence guarantees we'll be good at it."

There is not a rule against strategic bar use, but I have no special expertise on the interaction between Milliways and its patrons with prophecies of the sort your world generates. Your Security job comes with a room, which has a key, here it is, #1009.

"Awesome. Thanks. How do I find the bar when you need us to help out?"

You may find other doors in the future, although you are not obliged to sit a shift every time you encounter the bar. And here is a Security Handbook.

He flinches at the sight of it, then realizes it's probably written in his alphabet. "Cool. What does a second drink cost?"

That depends on what you would like. A second glass of wine like your first would be, and she names a quite reasonable figure in Dwarven measurements of precious metal, or you may opt to run up a tab; I can also take barter.