Plot summary
As Jack bonds with Claire, a recovered Locke turns down his offer of a surgery to make him walk again. Perplexed, Jack tracks down Cooper and finds him in a vegetative state, learning from Locke that he was the pilot of a flight (his first one) that crashed with Cooper aboard, crippling them both. Jack insists that he does not need to punish himself by refusing the surgery, but Locke leaves. On the island, the Man in Black saves Sawyer's group from Widmore but finds that Flight 316 is rigged with a bomb and decides to escape on the sub, which Sawyer asks Jack to prevent.
Jack pushes the Man in Black into the water and abandons Claire as the sub dives, but realizes that the Man in Black put the bomb in his backpack. Sayid dies trying to get it off the sub, while Sun is trapped under debris and Jin drowns with her as the sub floods.
Credits
Adapted from Wikipedia contributors, Lost season 6. HTML formatting and reference markers removed.