What's the worst nightmare you've ever had?

t is night time and very quiet. I'm in a large building with several other people. I don't know them well, but I'm comfortable around them. I feel we share something in common (job, circumstance). The building is a large facility. It's old, but not run down. And it's large. Like an old school or hotel. Lots of rooms and long hallways.

All five to eight of us are gathered at the main entrance portion of the building. It's well lit and feels comfortable and normal. I get the sense that there are only a couple of other people in this area, who aren't part of our group. They're employed there. Our small group is lining up and preparing to go into the other part of the building. The purpose of this 'mission' is part expeditionary and part kitsch. We're all aware that this other part of the building is unused and not maintained because of a presence that's there. A force resides in that part of the building that could no longer be explained away as coincidence or natural phenomena. The area had been conceded to this entity and was cordoned off as if it was a contamination zone. Someone in the group may have the intention of retrieving something. The mood seems serious with just a hint of whimsy added. 

We walk through the door and step down into the end of a long hallway. It's dark, with just enough ambient light to see things clearly but veiled in shadow. The floor is a mix of dirty concrete and wood, littered with bits of debris and trash. I'm near the back end of the group. We spread out quickly with each person going their own way. The floor plan is rather open, with large common spaces and lots of side rooms. 

I have the sense that something is there with me. Unseen but very close it knows I'm there. I feel confidently nervous as I proceed further into the facility. 

Other people are talking, pointing out various items of interest in low low tones. I can't see all of them but I know we're all fairly close to one another. We enter a spacious area similiar to a hotel lounge. There's a dusty broke down couch that looks like it could still support a person, but you wouldn't want to chance it. More litter on the floor. One piece of something has drawn the attention of several members of our group. I'm standing off to the side. Uninterested in the main quest, I'm there only to experience and observe.

On a small table in another hallway the remains of a large white bird are layed out. The bird is white with black fringed wings and a yellow beak. Possibly a pelican. It's on its back with it wings spread slightly and it's head twisted in an uncomfortable looking way. There's a little blood but I don't see any obvious wound. It doesn't appear the birds been there very long.

Something causes a stir with in the group who.are still over by the couch. I join them but don't see anything to cause alarm. We walk down a few more hallways and loop our way back, stopping at the table with the bird on it.

The table is illuminated with a well defined cone of light coming from an overhead fixture. It seems very bright given the darkness of the surrounding area. The bird is still there, laying in the same position but its head is gone. In its place is the freshly severed head of one of the women from our group. Her eyes slowly roll from side to side but they appear to not see anything. And her lips are twitching as if trying to form a word. Her head has been placed to look like it's attached to the bird.

We stand there for a minute in silence, absorbing the scene, and then begin walking. I can't tell whether we are headed towards the exit or deeper into the building. I'm lagging far behind everyone else. There's no sense of panic despite the display we've just seen.

As I'm walking I pick up something large and heavy. It feels like an iron bar but I have the impression that it's more of a digging tool. Feeling defiant and angry I slam the bar hard against the floor. The noise reverberates through the building. Moments later, as if a switch was thrown, all ambient light disappears. The resulting darkness is suffocating. It lays heavy over me stifleing the air. I feel enclosed but am still able to move freely. My sense of distance and direction are gone. I also feel that something is very near to me. I can't see it but I can tell it's looming behind me. It's big but does not have mass. A presence silent and dark possessing the power hell and completely focused on me.

I don't try to run. Having no concept of where I am, running would be pointless. I begin walking but feel like I'm going no where. The darkness is so thick and encompassing it's like being under water. Going through the motions of swimming but unable to tell if I'm actually moving. I continue making my way trying very hard to not do anything that would trigger a reaction from the being that has enveloped me. Making only the movements needed to walk and keeping my mind clear of any thoughts I proceed, knowing that if this entity senses that I have acknowledged its presence and power over me I have little chance of survival.

/r/AskReddit Thread