Garnering the Cult's Favor

From publisher blurb:

For as long as anyone can remember, a dark cult has plagued the land. Its members gather at night in carnivals of flesh; they perform dark rituals and carnal acts in orgies of necrosis and blood. They have been tolerated.

Recently, a faction of the cult has splintered off. This splintered faction has begun unfiltered killing throughout the city. In order to learn the origin of the splinter faction, the PCs must infiltrate them.

This is a free skill challenge for a group of level 6 players characters. They must pretend to aid as the splinter faction slaughters a group of the original cultists; they must make it look like they're helping to gain the cult faction's favor without getting any blood on their own hands.