When he gets to the hydrochloric acid somebody emerges from a side hallway, rushes him too fast to track with the eye, seizes it from his hand and flings it behind the bar where it vanishes, and whisks him into a room down that same hallway where she sticks him in a forcefield-barred cell.

What.

"Um. Hello?"

"No violence in the main bar area," she says, stomping over to the desk at the end of the cell-lined corridor, where she takes up position in a swivel chair next to an obsidian pillar.

"I- um. Okay."

Lucien is trying very hard not to feel guilty! Feeling guilty for throwing things at an unexpected demon is how he ends up dead, which remains very ethically dubious to undo.

"Would you mind me asking where this is exactly."

"You know, if you went up to the bar and waited for a napkin like a normal person, she would've told you."

"I'm....I didn't realize that was an option."

"Also there was a demon."

"Yeah. Lotta people come through here. He's not allowed to do violence either."

That's good to know.

"And you're capable of stopping him if he tries?"

"No, that's why I'm on double shift with that." She aims a thumb at the obsidian pillar. "It doesn't talk though."

Sure, why not.

"Okay. I'm uh, sorry for disrupting the peace in that case."

"Two hours subjective and then you can come out."

"Very reasonable. Thank you."

She picks up a newspaper and ignores him for two hours.

Lucien does not have any reading on him but he has a notebook and pencil and he can do some arithmetic to check if his brain's been tampered with, and when that turns out fine he can useless worry about the situation for the remaining time.

The forcefield disappears after two hours.

Is the apparently harmless demon still in the main bar area?

Yeah.

Stars explode violently and without sound beyond the window.

....Was that there before? Probably. Lucien was rather distracted by the demon.

He... has no further guesses as to what is going on. Which means his brain has been very very badly messed with - so badly he can't notice any sign of it - or this is genuinely something completely unexpected. The latter is basically useless to reason about, so he'll assume the former.

"Uh, I'm sorry for throwing all those vials at you. I was not aware there were safe alternatives."

"No harm done."

....

What if Lucien waits at the bar. And hopes a napkin shows up to explain what is going on. Like the weirdly fast lady suggested.

Hello there. Can I get you a drink? First is free.

"Uh. Water would be fine."

A glass of ice water appears. Water doesn't use up your free drink, so you're aware.

"I. see."

"Would you mind me asking where this place is?"