The Man In Black is the hidden but true main antagonist of the science-fiction mystery drama TV series Lost, which lasted 6 whole seasons. Also known as the "Smoke Monster" in earlier episodes and often glossed over for the first part of the series, it was shown in Seasons 5 and 6 that he is an enigmatic and evil entity born on the Island during the Classical Roman Era that seeks to free itself from the Island, which according to Jacob, would unleash great evil into the world and destroy it. He was originally the brother of Jacob, the Guardian of the Island, but became the Smoke Monster after Jacob threw his brother down the Heart of the Island, a source of mysterious power that the Island keeps, as revenge for killing their adoptive mother.