My first attempt to resolve the problem failed. At least I can narrow down the possible culprits now, hopefully. Unless it's not simply caused by completed quests...

I know the save I started from is okay. So, to keep track of the possible culprits, these are the quests I completed before entering the desert:

  • Holy Smite
  • Needs More Iron
  • That's Cold
  • Evil Puppy Cull
  • Leave No Witnesses…

I din't count She's As Cold As Ice and Slush Puppy Love (And Hate), because they're necessary to reach the dessert, so they can't be causing the problem.

Community content is available under CC-BY-SA unless otherwise noted.