As far as I can tell, the recommended level for this particular writ is set to too low. It feels like the recommended level should be set 2 or 4 levels higher.
In normal clear, apparently mages tend to get stuck on this quest. The fortress has hordes of enemies, the enemies summon hordes of undead, so by the time a small party would reach the queen, there will be no supplies or no magic spells left. It honestly brings back memories of the time when Malar temple was listed as level 14 writ. Main issue is that Corpse-Masters and Warchiefs can easily drain HP of an available summon, additionally apparently Corpse-Masters have infinite cast of Endure Element or something like that.
I've helped a mage character clear it out before with an epic level character. That was very easy, but that character was a melee ranger that had nearly 50 AC and 40+AB.
