Senlin Village is a small farming settlement located within a dense forest in the western Earth Kingdom. The surrounding woodland is protected by a typically peaceful, though occasionally enraged, spirit known as Hei Bai. Due to a lack of strategical advantage, the Fire Nation did not occupy this village during the Hundred Year War. The prevailing occupation of the settlement's inhabitants are farming and trading, though some villagers joined the army during the War.
Sometime before the spring of 99 ASC, the forest surrounding the town was burned to the ground by the Fire Nation as a result of a battle, an example of the devastation that the nation had caused in their endeavor for world domination. Having lost their home, the wildlife that once lived in the forest fled to other parts of the Earth Kingdom. However, the Black and White Spirit, Hei Bai, had guarded the village's forest for thousands of years and therefore remained in the woods. Hei Bai, furious that the his home had been burnt down, transformed into a frightening and destructive creature.
As the winter solstice of 99 ASC drew near, he sought revenge by attacking the village after sunset, destroying homes, and abducting people. Although Hei Bai was a spirit, the villagers were able to see him, because as the winter solstice drew nearer, the divide between the Spirit World and the physical world became thinner and thinner until it was blurred completely.
One villager sought help to save the village from the rampaging spirit. This old man encountered AvatarAang and his friends and invited them to the village. There, the village leader and the old man informed the group of the problems the spirit was causing. Aang's first attempt to calm the spirit proved to be a failure as many more buildings were destroyed and Sokka was abducted. When the spirit attacked again the next day, Aang was able to understand why the spirit was so angry and was attacking the village. He offered Hei Bai an acorn and promised him that there was hope for the return of the forests. Becalmed, Hei Bai changed back into the form of a docile panda bear and left the village in peace, returning the villagers he had taken.
After the Avatar and his friends left the village to travel to Crescent Island, PrinceZuko arrived, demanding that the villagers reveal the location of the Avatar in order to continue his pursuit.