I've searched everywhere for this guy. Not just in the encampment, but throughout the whole zone. I'm not sure if this quest is bugged, because if I talk to Dethmold to advance the quest "Conspiracy Theory", it then says that I've failed the quest to find Odrin. Any ideas?

I didn't take that route, but there's a game guide that came with the game that I'm sure tells you your answer (unless, for some reason, it's only a GoG thing and you didn't buy the game at GoG, but since even the first game came with a game guide, I doubt it).

Ah, I didn't even realize there was a guide. I guess I'll take a glance. Thanks.

If you don't want to look it up, a hint: there is more than one gate out of the encampment