Lômazar tells you of the ancient beast, Narchraw, that Dulgabêth wishes to treat with.
'If you seek allies of Dulgabêth, look first to an enemy of Sauron. Many years ago, a beast by the name of Narchraw crossed Sauron. He was locked away in the dungeons of Barad-dûr for his crimes. The dungeons can still be found within the ruins of the citadel.
'There are troubling rumours that Dulgabêth has spoken with Narchraw. Find the beast and kill it at once. If the tales are true, there are few as dangerous as Narchaw in the lands of Mordor.'
Barad-dûr is located in eastern Dor Amarth.
You should enter Barad-dûr.
Narchraw was said to be imprisoned in the jails of Barad-dûr.
You should follow the trail of scratch marks.
The chamber is scattered with debris.
You should inspect the various debris in the chamber.
Examined the chamber.