Sango notices that Inuyasha, Kagome, Shippo and Miroku had helped buried the graves of her fellow villagers. She uncovers the secret to passing through the barrier to a cave near her village where the shrine maiden Midoriko created the Shikon Jewel, able to purify the souls of the youkai. It is explained when a person contains the four spirits, them being courage, friendship, wisdom and love, at their maximum, they unite to form a really strong and powerful balance within the soul that can be used for either good or evil. (Source: Wikipedia)

Aired on: 5/13/2001