The prisoner visitor centre

You head down the barren corridor, passing by more corpses. It's not only the fact that you're walking down in an abandoned building full of corpses and possibly monsters, but the fact that the place is completely silent gets to you. Your steps echoing and sqeaking against the vaneered floor is the only thing you can hear. There is occasionally a lone fly buzzing around, but for a place with so many corpses you expected swarms of them. Something is not right here.

The prisoner visitor centre in itself is not very interesting, just a room with several tables where prisoners could sit down with their loved one or lawyers and talk. It's past this room where it's interesting. It's a corridor leading to a dead end with around ten cells on each side, each one barred with thick metal bars. Compared to the other parts of the station, this place is rather clean, though some of the unreleased prisoners now lie in their cells, forever imprisoned and rotting.

While looking around, something catches your attention. It's a sound, a sound of something beating, like giant footsteps. It's distant, but it's getting louder and clearer... Something big is heading towards you!