Before joining the Guild, Thrynn spent three years working with the same bandit clan that would raid villages, rob farms, and rob caravans. However, after attacking a caravan of farmers and rounding up the women and children, Garthek, the clan leader, ordered them to be killed. Thrynn refused, and Garthek ordered Thrynn to be killed as well. Those who were faithful to Thrynn sided with him immediately. The clan then tore itself apart, and Thrynn personally put Garthek's head on a pike. Those that survived went their separate ways.
- Thrynn is one of the non-essential Thieves Guild characters, making him killable.
- He is also one of the only people in the guild who doesn't change weapons every time the player levels up.
- In a conversation with Cynric Endell, Cynric asks Thrynn if it's true that bandits get "friendly with the wildlife." Thrynn responds by calling him an idiot.