Adventure Title
Jewel/Gem/Amulet of (the) Night/Midnight/Shadow/Darkness

Alternate title
Monster pick: Ghoul, Dweller, Serpent Folk, Abomination of the City

Opening Scene
A sewer system that is Foggy or misty where they encounter Natives that is/are Looking for a fight

Plot hook and draw
A fanatical layperson that is/has Attempted blackmail or extortion

Plot Concept
Overthrow the ruling elite that is motivated by An ancient feud

Primary Antagonist
A nefarious cult who/that is Obsessed

Plot fulfillment and location
Unwilling sacrificial victims from A pyramid lost to the desert