The Blood Heresy
Mitar Eythil is a planet that exists in the material plane. The material plane is surrounded by the asteral plane beyond which are the outer planes. To reach the outer planes from the material plane requires the ability to plane shift with a few noticeable exceptions. There are several places on Mitar Eythil that act as gates to other planes. Simply by walking to these places, one can be transported to a different plane.
One of these places is atop Mount Airis, the home of the gods. Those who survive the treacherous climb up the world’s largest mountain are transported to the plane of divinity. Simply surviving the journey is no guarantee of safety as the gods often do not like visitors.
It is said that if one travels deep enough into the caverns of Dragmire that one can reach the underworld. Dragmire is an underground kingdom that, although not evil, is not receptive to outsiders. Those that reach the underworld then face three rivers, one of mead, one of putrefaction, and one of fire. Only the devout and worthy can cross the river of mead and reach one of the seven heavens that lies beyond.