Publisher blurb: "Welcome to Mytherian Expansion: Zyrender, the Dark Elf Underworld. You must have the Mytherian Heroic Fantasy basic set in order to use this Expansion. In place of the Goblin Skull Keeps Adventure, you can now use Zyrender as the setting for new Adventures, challenges, enemies, and events. As before, when you set out from the city, you must first go through the Borderlands to get to the Wilderness where the Adventure layout will be. But instead of the Wilderness of Burnheed, once you successfully pass the Borderlands, you will find an entrance to the forbidding darkness of the Downland, a network of caves, tunnels, caverns, and passages—some created naturally, others hewn by unknown ancient hands—to enter the eerie underworld kingdom of Zyrender."