Thórhall is disturbed by the strange noises being emitted all around Lamab-dûm, and fears that the noise comes from the gredbyg that crawl all over.
'Strange sounds and strange creeping shadows surround us here... do you feel uneasy? I think it is coming from the north. There is a sickly light about that place.
'I have noticed a great increase in the gredbyg about this place. Perhaps it is their hive up yonder... will you go and thin their numbers? I will rest easier if I know there are less of them to crawl over me in my sleep!'
A swarm of gredbyg can likely be found in a hive in the Palance of Náin, north of Lamab-dûm in the Great Delving.
Thórhall wants you to kill off as many gredbyg as you can.
Thórhall is at his camp in Lamab-dûm in the Great Delving.
You should return to Thórhall and tell him that the grodbog presence is somewhat lessened in the hive to the north.