GUYS I JUST HAD A TERRIFYING EXPERIENCE

I swear to god this is no copy pasta, this just happened and for the love of me i can't find any info on it.

I was in Luminose City, one of many those buildings on the North or South sides that look identical inside and have an elevator and a bunch of random NPCs. Anyway, first floor was normal, NPCs chattering about random stuff. Went up to 2nd floor. Exited the elevator. My character froze and the music stopped, so I assumed it was a crash. Then, this female NPC I'd never seen before dressed in black with weird looking eyes comes out of the elevator behind me, GLIDES UP TO ME (THERE WAS NO WALKING ANIMATION I SWEAR TO DOG) and said something like "No... it isn't you." GLIDES OFF SCREEN, then the music comes back and I can move. That whole floor had the typical cubical layout but was empty. No people. Nothing. And creepy NPC was just GONE.

WHAT JUST HAPPENED PLEASE TELL ME I'M NOT THE ONLY ONE.

I was too scared to take a screenshot. Also I might've gotten the quote wrong but it was definitely "No... (something something)"

Not sure if this was scripted or triggered by something, feel free to ask me about my save at the time if you think it might provide an answer. Imma cry now