The Man in Black's final fate is determined, and one survivor must make the ultimate sacrifice to save the island. Meanwhile, in another life, the ones who might have been the survivors gather for a final time.

Jack, the new protector of the island, meets with Locke and they go past the bamboo field with Desmond to visit the heart of the island. The Man in Black's final fate is determined, and one survivor must make the ultimate sacrifice to save the island. Mea

Locke devises a new strategy; Jack's group searches for Desmond.

The motives of John Locke are finally explained.

Jack's suspicions about Locke make his decision more difficult after he is asked to complete a difficult task.

Alliances are forged and broken as the Locke and Jack camps merge.

Hurley agonizes over what the group should do next, and Locke is curious about the new arrival to his camp.

Sun and Jin desperately continue their search for one another, and Locke confronts his enemy.

Richard Alpert faces a difficult choice.

Locke tasks Sawyer with a mission.

Ben deals with the consequences of an uncovered lie.

Sayid faces a difficult decision, and Claire sends a warning to the temple inhabitants.

Hurley must convince Jack to accompany him on a mission, and Jin comes across an old acquaintance.

Locke goes in search of aid to further help his cause.

Kate finds herself on the run, while Jack is tasked with something that could put a friend's life at risk.

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

The aftermath from Juliets detonation of the hydrogen bomb is revealed.