Templars Against the White Brotherhood(Martial Arts, Middle Ages 1, Illuminati)
A group of Knights Templar, Weapon Masters all, are sent on covert missions to combat the rising power of the White Brotherhood, a secret society of magicians, alchemists, diviners and necromancers, who meddle in medieval affairs for their own benefit.
This is on my list of campaigns I'd run in a hot second. I have the start of the White Brotherhood in my C&S notes. And building the Knights-Templar templates, the special forces of their day, would be amazing.
The Sons of Freedom - Squish!(Illuminati, Goblins, Reign of Steel)
In this darkly humorous future, the robots have taken over from the Goblins. In their fight for freedom, the Goblins band into secret societies to combat the android mechanicals. Much slap-stick involved.
I have some weird friends that would be amused by this. I think I'd go nuts.