Boone Carlyle was aboard Oceanic Flight 815 after having gone to Sydney to (once again, it seemed) rescue his stepsister, Shannon, from an abusive relationship. During this trip, Boone and Shannon have a one-night romantic encounter, which seems to have been a long time coming, and they agree to pretend it never happened. Nonetheless, Boone has an overbearing, protective relationship with his sister, which she resents at times. He is an L.A.-based CEO of a clothing company that is a subsidiary of a corporation owned by his mother. On the island, Boone quickly develops a bond with Locke and all-too-willingly joins him on his expeditions around the island.