Lost (season 6)
On the island, it is revealed that, long long ago, infant Jacob and his brother were stolen, from their birth mother, by a woman who raised them to become protectors of the island, after her. At the hidden center of the island, is a waterfall cave containing a bright power source. Jacob (with blond hair) and his brother (with black hair, symbolizing white and black) grow up with opposing viewpoints. Jacob stays loyal to his adoptive mother, but his brother joins with outsiders on the island. When the brother reveals that they have dug into the core of the island, tapping an underground power to escape, the mother hits the brother with a rock, and she destroys the people in their village. She then chooses Jacob to drink the water of immortality. His brother awakens to see the burned village, and seeking revenge, he finds and kills his adoptive mother. Jacob discovers her dead body, and in turn, throws his brother into the waterfall cave, transforming him into the black Smoke Monster.