A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.
As the players travel along the trail, they notice a bear in the woods, following thier moves. It does not make any agressive moves, but neither does it leave. As daylight fades, the players need to decide what to do. Is it a spirit guide, or gaurdian to the forest; is it a lycanthrope, or being controlled by evil spirits; or is it just a curious bear?