[Serious] What is your most terrifying "we need to leave, NOW" random rush of fear you've felt?

I was shooting a scene for a student film at a graveyard at night during the fall. It was through the graveyard, by a church-like building. We had brought lights and everything so it wasn't too spooky.

I was the audio guy so I had a zoom recorder and headphones and while the other people were setting up I ventured off a bit towards a big wall of forest. I figured I'd just get some room tone so to speak, so I started recording towards the forest and I very quickly became very uneasy. I was wearing headphones so the sound was amplified but I was off in the darkness and the wind through leaves sounded just like a monster crawling quickly after me. I immediately went back to the bright lights.

We didn't even end up using the scene anyway

/r/AskReddit Thread