The GravewallThis long curtain wall of gray marbled stone stretches across the nearly 10-mile length of the Grand Cavern, from Rak Kuldrest to Rak Surest. The exterior of the wall, facing Karhr-Syharwehrf and its surrounding Blasted lands, is etched with intricate, interlocking runes and glyphs which radiate a skin-tingling potency, even to those who lack the gift of magical senses. Along the interior, the stones are bordered with similar runes, the center of each bearing glyphics — a dwarven family name, followed by the epitaph “Defender of the Empire, even in death.” Originally a soldier’s monument, after the Glittering Empire began to crumble, it became compulsory for all citizens to be interred within the monument.
When any of the twelve horns at the watchpoints along the top of the wall are blown three times, the sorceries laid on the wall activate, animating the corpses — mostly as skeletons, but occasionally as zombies, for the freshly-interred. Those of high nobility, who could afford the special rites associated with the passing of the head of a noble family — animate as wraiths, or in the case of those of the highest class, specters.
While engaged in battle within five miles of the wall, the animated undead reduced to 0 hit points will re-form within 1d6 rounds, taking up arms to fight again(and again, and again….).
When the all-clear is sounded from the horns atop the wall, the undead turn, and march back to their graves, to sleep again until needed by the Empire.
Humanoid remains not removed from this five-mile expanse will likewise be claimed by the wall after nine days (the traditional length of a Dwarven mourning), rising up and marching to find rest in the catacombs beneath the Wall, where the dwarves interred criminals and those who could not afford burial within the wall itself.