Welcome to the Land of Mists. This is a RAVENLOFT campaign using 5th Edition D&D (Next) rule set.
Beyond mortal senses, beyond your reality, there lurks a boundless plane. It permeates your world and fills the void between worlds. It is the border between the lands of the living and of the dead. There, mind and matter become one; thought and passion, fear and yearning can become more tangible than iron, It is the Ethereal Plane.
Somewhere, lurking deep within those ethereal mists, a dark and nameless dimension is ruled by dark and nameless powers. Some say it is a prison for the damned; some say it is a crucible to test the virtuous. Others simply call it home. It is a land of mist and shadow, love and death, sacrifice and seduction, beauty and horror. It is a land of whispered fears made manifest. It is the Realm of Dread.