Can you help me find this movie/tv show with a scene in a 50's diner?

Hey all, so very vague, but something that I just had a weird recollection of, I recall a movie, or tv show or something extremely vaguely, that had some sort of cafe, or 50’s diner that was “hidden” somehow, and was used as a meeting place for some special group of people, not sure what it was.

I kind of thought it may be supernatural, but I don’t think so, it wasn’t something public people could get to.

I was wondering if anyone else might have an idea of what this might be from.