Before the dawn of the Third Age, the kingdoms of Rhudaur, Arthedain, and Cardolan stood in opposition to one another at the cross-roads of the Lone-lands. As Rhudaur fell to vile corruption, some Men of Arthedain were held responsible for the desecration of the land, and they have long waited to see a time when they could make amends for their greatest failures.
'Of deeds, we were the same. In name, we shared our last. Lost to us through death, returned to us through the shadow which grows in this land. He is not what he was. There is no memory there, there is no knowledge of what came before, but the body rises and must be laid to rest.
'I speak of our brethren, but not so. I truly speak of the thing called Gostoth which wanders the depths of the ruins west of Ost Haer.
'Seek thou this creature and destroy it, lest it plague us still.'
Gostoth may be found in the ruins west of Ost Haer.
Narthan asked you to search for the creature Gostoth and destroy it so he can know that his brethren's body is at rest.
Narthan is at Ost Haer.
You scoured the ruins west of Ost Haer and discovered the creature Gostoth. You should now return to Narthan and tell him that his brethren is once again at rest.