You have come with Orvar Bellhammer to Zurr-thurkh, the 'secret road' that was built as an escape passage from the throne room of Durin, and will use it to gain access to Mazog's fortress.
No one has walked the 'secret road' since before the Fall of Moria, but now you and Orvar Bellhammer will use it to get behind the walls of Mazog's fortress, Zabadgathol.
You should clear the way for Orvar to follow when he is ready.
Orvar is waiting outside the secret road, in Rushdurinul.
Orvar has told you to search the large Orc encampment in the throne room for the captive Bori.
With no sign of Bori in the Orc encampment within Rushdurinul, Orvar has decided to confront Mazog directly.
You have come with Orvar to Rushdurinul, the throne room in which Mazog makes his lair, and will now confront the Orc leader.
With the sudden appearance of Bróin and the Elves from Buzun-ghâr, Mazog has been defeated.