Signs

I come back to the abandoned building to show Tom; somewhere private. I try to show him how I know where it is on my laptop, but then-I hear a door creak. I turn around and find an opened door, still moving. "Wait a minute." I say to Tom. "What?" He replies. "Stay there." I tell him. "No-" I run towards the door and walk in. I walk across a wall colored blue with orange paint showing a sentence. This is that sentence: The last man on earth sat in a dark room. There was a knock on the door. "2 Sentence Horror Stories?" I think out loud. I look behind me. The door's locked.