From Introduction: The shadowslayers of Gaureth are a mix of guild assassins and arcane cultists. Born of a group of arcanists exploring the side effects and origins of magical darkness, the shadowslayers themselves are purposefully infected with umbral fever in a dark ritual. The original shadowslayers were recruited from an assassin’s guild, and now the guild (The Shadows of Gaureth, named after the city of their origin) has become nearly dependent on the arcanists who discovered the potential side-effects of the umbral fever infection.