Deep under Járnfast, chief fortress of the Iron Hills, is a place where the red stone once cracked, revealing a horrible abyss beneath the Dwarf-halls.
'As I peer into the abyss my mind begins to cloud. There is both shadow and madness down there. I fear our only option is to enter the pit and hope to bide us some time until the seal can be repaired. If you are not able, I understand, and will send some of my best warriors instead. What choice do I have? If nothing is done, doom is certain.'
WARNING: This is an extreme challenge instance suited for a 3-Man Small Fellowship. Proceed at your own risk!
Náin can be found at the entrance to the Howling Pit in Járnfast.
You should talk to Náin.