This theme will play in many dungeons/adventure fields/whatever you want to call them throughout all four seasons. The first time it is heard however, is at the beginning of season 1, when Verse and Xan have been thrown out of a town for inciting a huge bar fight. Bereft of money, and with nothing but their weapons, they were dumped miles and miles outside of town, in a dense forest full of monsters. This sounds like a great way to start off a day, doesn't it?