The Castellan from Tarterus

From the introduction: Four long nights of unholy terror extinguish the quavering custodians of Istiernabor Castle! Pronounced the grandest work of two kingdoms, the newly completed citadel was home to a unified troop of Men and Dwarves. Vexing reports from the area fail to assert which dire creature orchestrated the siege. Without a rationale for the grave loss, one realm may be accused of inability to amply defend the borderland! Perhaps the mounting turmoil can be eliminated by an elite contingent that only wants Istiernabor liberated?