The Portals of Lavar
Dozen of generations past, the world of Lavar experienced the Rift, an apocalyptic event that separated the world into hundreds of Refuges. The Refuges are what little remains of the Prime Material Plane. Islands of stability amongst a sea of chaos.
While they are always rumors of Riftwalkers, beings able to come and go as they please among the Refuges, it is common knowledge that to walk into the Rift is to be never seen or heard from again.
And so time past, with life in the Refuges going on, always isolated except for the random raids of various monsters raiding from the Rifts until the Ways where created. A mysterious organization, the Cabal, discovered a method of creating stable connections between various Refuges.
Suddenly, the isolated people of the Refuges where once more able to interact with each other.