Post-apocalyptic science fiction is one of my favorite sub-genres. Finding a good fantasy equivalent can sometimes be difficult, as it usually gets classified as science fiction. E.E. Knight’s Way of the Wolf has vampires and magic, and clearly falls into the category of fantasy. It also is about a post-nuclear United States with aliens, and scattered communities of humanity fighting for survival. It’s a strange mix, but it all works out well.
In the 2020’s a series of natural disasters struck earth,