Charlottesville Coal Tower
Modified under licence from here.
There are countless dangers - the atmosphere was seeded with pockets of poisonous gases that drift through unpredictably or settle into hollows invisibly. The biological weapons, now freed of any tenuous constraints they might have once had, breed and mutate, giving rise to thousands of ingenious horrors. Engineered vampires stalk the lands, obeying the loose prerogatives programmed in by biochemists years before. Vast snake-worms burrow through the churned mud, swallowing people whole. And any human you meet may be more dangerous still, toting guns, chemical grenades, and a will to live at your expense.
The fortified labs that were built during the later years of the war are still dotted across the dying landscapes. Tribes that can gain access to one have a defensible home. These squat buildings are the castles of the modern age, encased in thick concrete that can withstand all but the heaviest bombardment available to the survivors, and defenders on the battlements can rain death upon would-be invaders. These aged chemical keeps shape the conflicts and lives of the surrounding land.
And then breaks freeUsed under licence from here.
In the Grey Keep, for example, containment procedures for entering and leaving the lab through the airlock doors are still in force - despite the gaping holes in the walls. Anyone trying to enter or leave through those is summarily vaporised, as is anyone who drops anything liquid in the lab and fails to reassure the AI that "It's just coffee", echoing the words of a long-dead researcher the AI still remembers.
Some keeps have - carefully avoiding the AIs neuroses - widened and dressed holes in the lab walls, so that invaders who gain access don't know which doors are acceptable to the resident AI and which are against proper protocol. Other keeps have AIs that can identify vampires and eliminate them, but in most keeps they aren't so lucky.
A post-apocalyptic setting piece.
Used under licence from here.
I liked the idea of bio/chemical apocalypse, as opposed to a nuclear one. In many ways, it seems to me to give fictional justification both to a more multi-faceted area-based danger than radiation - gases, viruses, pools of liquid mercury - and a more flexible creature-based danger than mutation from radiation exposure - engineered viruses and straight-up constructed monsters. And, of course, biological weapons have just as much potential to wipe out huge swathes of population. Perhaps more, if less suddenly.
The other idea I had, which I then weaved in, was the idea of enforced superstitions: What if there were a community of people who all followed these weird little superstitions - you have to say certain phrases when you do certain actions, you have to go through certain doors backwards - because there was an AI that was used to the way things used to be and couldn't adapt to its present circumstances. I think there's a lot of potential there for dark humour.
In a bit I may post more about defensive structures in environments with gunpowder. I have Learned Things about this in the making of this post.