On the world of Mym, meaning "Foggy" in the language of the First Ones, the people live on the coasts and on islands.  A dense fog exists inland, starting a few miles from the coast.  The fog is toxic to most lifeforms, causing humans to loose consciousness within seconds of breathing it and killing them in less than a minute.  Other races may last longer, but all eventually succumb to the poisonous fog.  The water and the wind which blows across it keep the fog at bay.

From time to time portals open up from other worlds, bringing people from those worlds to this one.  Those unfortunate enough to be brought to this world into the fog die, but those brought to the coasts, islands, lakes, rivers, or oceans generally live.  This has been known to occur for thousands of years, since the First Ones documented it over 12,000 years ago.  Unfortunately, there are only a few of them left, most having given their lives protecting the other races from the monsters that live in the fog, and the few remaining being too far spaced out to rebuild their population.

The Monsters come out from time to time to take people back with them.  While some say they are being kept alive as slaves through some unknown means which lets them live in the fog, most people believe that they are a simple food source.  The fact that the monsters have as much trouble outside of the fog as we do in it means that encounters are rare.

A few days ago an elf woman wandered into town.  She couldn't remember much, but she did remember a lake within the fog, and a series of tunnels which led there.  While she feels she must return, there are few, human, demon, or other, who wish to risk there lives for someone they don't know.