Bernhardt and Azguz enter the pass from its south side. They are awaited by two regiments of archers, which must not be a big problem. But after reaching the first branching they get into an ambush and are attacked by a huge party of undead. An immediate fallback is recommended, to charge the enemies with long-range-weapons. After finishing this wave of attacks, unfortunately it is not yet done, because short before the end of the pass there are some more regiments of undead marching against you.
If you have finished this challenge sucessfully, you will be given an enchanted shield by Azguz Blutfaust.