The Plague Pyramid

From publisher blurb:

A new cult has arisen, worshipping death by plague and its locus is somewhere in the hinterlands, centered around a bizarre structure. Whether the plague pyramid is the result of a mad necromancer’s experiments with the mcguffin or whether the magic inside simply a response from a traumatized plague-ridden land itself is unclear. Either way, thousands of refugees have abandoned the cities and staggered mesmerized toward the infested pyramid, where a Plague Jester urges them on to the most debased and degrading acts.