Amethyst, a lively and mysterious young tiefling woman with a penchant for long, shimmering green dresses and high society parties, secretly leads a society of spellcasters.
As far as most people know, she’s simply an independently wealthy ex-adventurer with an infectious laugh and a shrewd mind.
But several nights a week, she meets with others of her kind in basements all across the city, where they train each other in magical combat. These fights can be very hard, but they’re not intended to kill or even hurt. They’re meant to toughen. Each member of her organization has embedded a small jewel somewhere on his or her body, typically in the middle of the breastbone.
Amethyst believes in a coming sea change in the public perception of magic. She believes that a purge will sweep civilization a few years from now, where the common people will rise up out of fear of magic and hunt down spellcasters.
So her followers train to defend themselves on that day, and they’re building a secret stash of magical tomes and records that they can keep safe through the upcoming purge.
As a friendly faction, Amethyst and her Jeweled Ones are a slightly crackpot but ultimately benevolent group. Amethyst is misreading various political signals, and her organization serves as a diversion and sort of insurance just in case the worst does happen. They can be treated like UFO hunter “true believers.”
Amethyst can hire the adventurers to search for various arcane books that are lost deep in dungeons, abandoned temples, and other suitable adventuring environments.
As a foe faction, Amethyst is a seriously disturbed person who’s convinced herself of an upcoming apocalypse. The Jeweled Ones train furiously and acquire magical knowledge through any means necessary. And anyone who finds out about them and talks of them publicly doesn’t survive long.
Basically, they’re a cult that are rapidly becoming terrorists.
The PCs may be hired to investigate a murder that was committed by a Jeweled One to silence the victim, or to find a magic tome before they do (a la Indiana Jones and the Last Crusade).
A showdown with Amethyst and her followers can occur in the following map, which can be either a sewer or basement complex. Entry comes through the left, and Jeweled Ones will hide in room 1 until the PCs enter room 2, then pour out to meet them. Amethyst will be waiting in room 3.