
After the first time a hero is infected with the Curse, the Fanatic will appear in town, and from then on will stalk any party with a large number of infected Heroes in it.

Exploration into the Courtyard and encountering Bloodsucker enemies presents chances for members of your party to be infected with the Crimson Curse, a persistent and nigh-impossible to cure disease akin in several ways to vampirism. The Courtyard also modifies gameplay for the rest of the game in several significant ways. The Courtyard is a location added in the Crimson Court DLC - the former lavish gardens and vistas of the estate, fallen to ruin and overtaken by a terrible, bloody insect-borne infestation and its depraved victims.

~ The Narrator on entering a expedition in the Courtyard

Soaked and sinking, these stone terraces and sprawling gardens are the site of long forgotten revelry.and well remembered regret.
