The Fog is the epitome of the unknown, a white sheet of rolling mist obscuring anything beyond it. No one knows what the Fog is or why it holds steady around Homelands and never moves in, only that it consumed the old world during The Reversal. People who go into the fog rarely come back out. Those that have returned say that it’s like walking blind, unable to see more then 5-10 feet around you in any direction. Many creatures called the mistborn have adapted to living within the fog, their vision tends to be weaker the further into the fog they live, but all their other senses have sharpened allowing them to hunt and survive in the fog.
The fog rolls in and out like a tide against the shore, when the fog rolls back and exposes the old world underneath it also leaves behind some of the mistborn, when outside the fog the start to get more aggressive and move to find a new home and feeding ground. boredertown are always preparing for low fog, ready to fight off any mistborn that inevitably come with it. Some people called Runners explore the ruins of the old world during low fog. They can find many treasures there but they face the obvious dangers left behind, the worst of which is still being there when the fog rolls back in.