The Secret Revealed (spell)

Unique spell cast by consuming charges of the item by the same name, a holy gem given by Brother Deepvein in The Dig.
While immediately intended for Coldhearth, it also works on the later optional boss Zhadroth, the only other lich in Siege of Dragonspear
== Gameplay ==
Effect details:
* vs. undead (Save vs. Wand for half)
* Miscast Magic on undead (80% casting failure, no save, no dispel)
* Remove Combat & Special spell type protections on undead
* Remove BDLICH.itm, a non-droppable ring equipped on liches in , which grants:
** Un-targetable by summoned demons 
** 90% resistances to cold and electricity 
** Immunity to normal weapons 
** Immunity to level 1-3 spells, in addition to Holy Smite, Skull Trap, Call Lightning, Cloudkill, Silence, 15' Radius, Unholy Blight, Glyph of Warding, Web, Stinking Cloud, Entangle, Sphere of Chaos, Polymorph Other 
** Immunity to sleep, power-word-sleep, slay, paralyze, polymorph, hold, disintegrate