The Trollskull Companions take the fight to the Drow deep within Undermountain! Using clever tactics and a risky split-party strategy, the heroes strike from both above and below—melee fighters clashing amidst the Drow ranks while spellcasters unleash devastating magic from a cliff overlooking the cavern. But even with the advantage of surprise, danger is never far in the Dungeon of the Mad Mage. Will their plan hold, or will Undermountain claim more victims before the battle ends?