Bósi believes another of Gorothúl's relics may be found at the bottom of Nalâ-dûm, where the great wheels of Khazad-dûm lie dormant.
'My uncle Bósi sent word while you were out. He thinks he knows where another of Gorothúl's relics may be found, and the location is just as dangerous as Lumul-nar, if not more so: the Water-wheels of Nalâ-dûm.
'Travel to the Chamber of the Cross-roads with your allies and speak with my uncle to learn more about Nalâ-dûm.'
Bósi is in the Chamber of the Cross-roads, located off Durin's Way.
Bróin has told you to speak with his uncle about the Water-wheels of Nalâ-dûm.
The entrance to Nalâ-dûm can be found in the Water-works of Moria.
Bósi reports that a relic of Gorothúl's lies among the Water-wheels of Nalâ-dûm and will require careful usage of the mechanisms to reach and destroy. He also recommends you bring an ally or two.
Bósi is in the Chamber of the Cross-roads, located off Durin's Way.
You have destroyed the relic left in Nalâ-dûm by Gorothúl and should report your success to Bósi.