A good camping-place with something extra: a gallows with a hangman, reduced mostly to bones and a few rags. It marrily hovers in the wind. Any manipulation will make it fall apart. An excellent camping place, except for the midnight hours, when ghosts of those executed haunt here. Some wail for their crimes, some re-live their execution over and over, some want to have a talk, and still some others want to scare the Living for fun.
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.