When Locke learns that Boone wants to share their "secret" with Shannon, Locke decides to teach him a lesson. Boone and Shannon's dark past is revealed in a shocking backstory that recalls their relationship right before the plane crash. Kate, who has become a confidante to the soft-spoken Sun, is puzzled by Sun's mysterious behavior. A hungry Hurley must convince Jin to share his fish by making up for offending Jin by rejecting his offer of raw fish early on, or he'll continue to suffer digestive problems from the limited island diet.