06E15 - Across the Sea

A shipwrecked pregnant woman named Claudia comes to the island and is rescued by an older woman and immediately after she delivers two babies: Jacob and another boy; then, the woman kills Claudia. She raises the boys as if they were their sons and one day they see three men in the island. She shows a cave with a bright light inside and she tells them that they shall protect this light. One day, Claudia appears to her other son and she shows the survivors of the shipwreck living in the other side of the island. She tells what happened to her and the boy calls Jacob to go with him to live with the other people; however Jacob decides to stay with his foster mother. Jacob secretly visits his brother to see where his people are bad or not. His brother tells that will leave the island and Jacob tells to his stepmother. She destroys all the humans and assigns Jacob to protect the light in the cave. Jacob's brother kills their stepmother and Jacob throws his brother in the cave, where he transforms into the smoke monster.