Screaming or howling

I was in a mall, but somebody mentioned that the ground, or underground, floor is full of zombies, or at least people pretending to be zombies. It seems we can access it only via elevator. For some reason, I ended up there, and I was outside of the elevator. It is a room of sorts. I cannot move. I can see the elevator. I started to hear zombie moans and shuffles. I saw the elevator still open, and one "zombie" walking close to it. Then I saw one behind me. I was kneeling or sitting on the ground, stuck. My vision showed a crosshair as I panicked. I think I "know" that they are just pretending, but it is still scary. I was in the elevator again. The inside looks like a wall, with rough texture. There are three buttons, arranged in a column. The top floor, the middle (regular) floor, and the underground floor. I tried pressing the middle button, but I saw that the bottom button has already been pressed. I was with other people in the elevator. The door to the underground floor opened, and the zombies were there. As they enter the elevator, they become "normal" humans. I was wondering what the top floor contains, but never got the chance to press it. I was in one of the "outside" areas of the underground. It looks something like a mine. There was a lady, asking for directions. Somehow, she went to the elevator area. I heard her scream, and then laugh at the zombie prank.