Thonnir is married to Laelette, who has gone missing. Speaking to him after investigating Hroggar's house will take Laid to Rest to the next step. Following the quest line will reveal Laelette was turned into a vampire by Alva, a woman who was turned into a vampire by Movarth. Alva seduced Hroggar, a widower whose wife and child, Helgi, were victims of a house fire. Laelette attempted to turn Helgi, but failed and Helgi was left to burn in the house.
After Laelette dies, Thonnir denies that Alva could have turned her, stating that Lalette must have "met her fate out in the marsh". Towards the end of Laid to Rest Thonnir will aid the Dragonborn in killing the master vampire while the rest of his companions will coward away.
If the Dragonborn asks Thonnir to aid on the quest, but does not complete it, Thonnir will join the Dragonborn as an immortal helper. This does not take up a companion slot.
See the main article Multiple Followers.
Thonnir is one of the quest characters that can be exploited to follow you throughout Skyrim along with a follower of your choice. It should however be noted that while he will indeed follow and fight for you, he cannot be commanded or equipped. Neither will he enter sneak or sheath his weapon. While not strong he cannot be killed, making him quite useful as a decoy.
- When talking to Hroggar during the quest Laid to Rest, he says that Thonnir used to beat Laelette, his wife. It's unconfirmed whether this is true or not.
- The Elder Scrolls V: Skyrim (First appearance)