The Last Ceremony

From publisher blurb:

This is the fourth installment of the brochure adventure series. Similar to my one-page adventures, these include everything in the brochure and they are all system neutral. This one-shot adventure is about a strange cult known as the Congregation of the Crawling Slime. Their leader conscripts people every day and they gather underground in what appears to have been a forgotten temple. Unknown to most of them, their leader is under the influence of a poison. Some strange worm-like creatures from the Underworld have made him believe all the nonsense he claims as a new religion now. Worst of all is the fact that the leader sacrifices a person every day to keep the worms at bay.