Hugin is involved in the quest "Family Matter".
After Hawke enters Bartrand's Estate with Varric Tethras, Varric meets up with Hugin, who then tells him that after Bartrand left Varric and Hawke to die in the Primeval Thaig, he started hearing voices, claiming the lyrium relic taken from the thaig was talking and singing to him. At the same time he was scared by it and on one of his 'better days' he sold it. Unfortunately, he could still hear the relic and was eventually driven mad by it.The steward tells Varric and Hawke that Bartrand started feeding the servants and guards lyrium to make them hear the 'song' and became increasingly mad as no results materialized, to the point when he started torturing the servants and 'cutting bits off them while still alive'. Hugin begs Varric and Hawke to give anything alive in Bartrand's study a quick and merciful death before fleeing.