After finding out that Ben killed Jacob, Ilana decides to kill him. Meanwhile, Jack, Hurley and Richard visit the Black Rock. In flash sideways, Ben is a teacher at a high school and tries to make a power play to become principal.





After recruiting Sayid to his cause, the Man in Black issues an ultimatum to the Others: either join him or die. Meanwhile, Kate is reunited with Claire. In flash sideways, Sayid helps his brother, who is in debt to a loan shark.





Fearing the safety of the Oceanic survivors in the temple, Jacob’s ghost instructs Hurley to lead Jack to a lighthouse. Claire shows signs confirming that she is Infected while questioning an Other she has captured and tending to an injured Jin. In flash sideways, Jack and his ex-wife have a son who is an accomplished piano player.





On the island, the Man in Black attempts to recruit Sawyer in his attempt to leave the island, while Sun insists on burying the body of the real Locke. In flash sideways, Locke is fired from his job and becomes a substitute teacher.





When Sawyer leaves the temple, Kate and Jin are sent to bring him back. Meanwhile, the Others determine Sayid to be infected and attempt to poison him. In the flash sideways, Kate, still on the run, takes Claire to a hospital when she goes into labor.





Two outcomes of the detonation of the hydrogen bomb are presented: In the first, Flight 815 lands safely at LAX, where Kate escapes from the marshal and Jack learns that his father’s body was lost in transit. In the second, the survivors return to the present day after Jacob’s death; Juliet dies and Sayid is resurrected after being brought to the Others’ temple. Also, the Man in Black, who is impersonating Locke, is revealed to be the Smoke Monster and kills several of Ilana’s team from Flight 316.





The aftermath from Juliet’s detonation of the hydrogen bomb is revealed.





A chapter in the crash of Oceanic flight 815 on the mysterious island spotlights inhabitants, questions that have been answered, and those that remain a mystery.





In 1977, the survivors succeed in detonating the modified nuclear bomb at the construction site of the Swan station, the finale ending when the bomb is detonated. In 2007, Locke and the Others travel to the base of the four-toed statue, where Jacob lives. Locke is revealed to be an impostor: an old acquaintance of Jacob who tricks Ben into killing Jacob. In flashbacks, Jacob visits several of the main characters.





In 1977, the survivors succeed in detonating the hydrogen bomb core at the construction site of the Swan station, with dire consequences for several characters. In 2007, Locke and the Others travel to the base of the four-toed statue, where Jacob lives. Locke is revealed to be an impostor: an old acquaintance of Jacob’s, who tricks Ben into killing Jacob. In flashbacks, Jacob visits several of the main characters.