The Greater of Two Evils

I have no doubt this Zumwald serves the same dark master as the murderous raiders pouring from the north. And what a weapon they have now: a plague to soften our defenses just as their barbarous army attacks. We know the names of three doctors. Wirt, Fiegler, and Zumwald. Fiegler's corpse you found, and my scouts have located Wirt. Initially I wanted him brought back alive, but if he is as plagued as you say, I'd rather you burned his corpse and buried the ashes far from human civilization.

Find and kill Doctor Wirt. Return to Elector Count Valmir Von Raukove outside Wolfenburg once the accursed plague-doctor has been dealt with.