A land being plunged into chaotic energies, wild superstition, massive prejudices and distrust. More of a campaign setting than anything else.
This is more of a concept applied to a particular setting than the setting itself, bear this in mind.
In the harbour of a major city a large and terrifying ship made of human nails docks. Nobody seems to inhabit this ominous vessel, someone needs to go on board and unveil the mystery. In comes the PCs.