Castles in the Sky: Apocalypse World [ EDIT ]

It's the end of the world. Based on an idea from the AW subreddit, posted by an author who then deleted their account. The world is covered in toxic mist, but the death fog is heavier than air: it pools, running like a poisonous river into valleys and city streets. A new form of civilization arose atop the structures of old, first in the form of huddled masses crowded onto the roofs and upper floors of larger buildings. Time went on, trade and communication arising between buildings as brave, agile transporters found ways to navigate the ruins. Now, intricate spiderwebs of rickety bridges, abandoned cranes, steel girders, and occasionally crude dirigibles allow access to much of the city once more, facilitating both the sharing of culture... and war. Scavengers clad in salvaged scuba gear descend into the toxic mist to gather what they can and flee back into the light before the twisted things lurking within catch the sound of the heartbeats.