Season synopsis
Contains spoilers for this season and earlier seasons.
After Ben turns the island's wheel, the survivors left behind jump between different periods, including the island's early encounters with the Others and the Dharma Initiative. Locke eventually stops the shifts by moving the wheel himself, then leaves the island to gather the Oceanic Six. The group resists returning, but flight 316 brings Jack, Kate, Hurley and Sayid back to the island; Sun and Frank remain in 2007, while the others arrive in 1977. Locke's body also arrives, although the man who appears as Locke is not the real John.
The island survivors become stranded in the 1970s and join Dharma under assumed identities. Sawyer, now calling himself Jim LaFleur, and Juliet build a life inside the settlement, while Jin, Miles and Faraday help keep their history hidden. When Jack, Kate and Hurley reappear in 1977, Sayid is captured as a suspected hostile and shoots the young Ben Linus. Jack refuses to operate, so Kate and Sawyer bring the wounded boy to Richard Alpert; Richard warns that saving Ben will erase his memory of these events.
Faraday returns with a plan to use a hydrogen bomb to prevent the crash, but his mother Eloise shoots him before he can act. Jack and Sayid later carry out the plan as the Dharma drill reaches the island's electromagnetic pocket. The bomb does not detonate on impact; the pocket opens, metal is pulled into the pit, and Juliet falls into it. She survives long enough to strike the bomb with a rock, triggering a white flash. In 2007, Ilana's group reveals the real Locke's corpse in their crate as his impersonator persuades Ben to stab Jacob.