Two outcomes of the detonation of the nuclear 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.
(From Wikipedia)
