Stripped of everything, the survivors of a horrific plane crash must work together to stay alive. But the island holds many secrets.
Charlie begins a painful journey of withdrawal from drugs, surprisingly aided by Locke, whose true motive for helping Charlie is a mystery. Meanwhile, survivors struggle to find and free Jack when he's buried alive in a cave collapse, and someone might be secretly thwarting Sayid, Kate, and Boone when they enact a plan to find the source of the French transmission.
Shannon's inhaler runs out and Boone believes Sawyer has the remaining three in his stash. When Sawyer refuses to give them up, Jack and Sayid resort to torturing Sawyer until he agrees to reveal the location of the inhalers. In flashback we hear Sawyer's story and find he is not who he says he is.
Sayid's life is placed in grave danger after he stumbles upon the source of the mysterious French transmission, the woman Danielle Rousseau (guest-star Mira Furlan). She was on the distress call and is found alive. Meanwhile, Hurley has a ridiculous plan to make life on the island a little more civilized. The plan involves golf clubs he finds in the debris, and it looks like it just might work. Lastly, we flash back to Sayid's childhood friend Nadia as well as his participation in hostage situations in Iraq.
Claire has a horribly realistic nightmare about her new baby being harmed or kidnapped. Flashbacks reveal Claire's backstory: the former boyfriend who got her pregnant, then abandoned her, and the psychic who convinced her to take the ill-fated flight that landed her on the island. Hurley is shocked and confused when he discovers that Ethan Rom (guest-star William Mapother), another plane crash survivor, does not appear on the flight manifest.
Survivors wonder why Charlie and Claire have been abducted - and by whom - and a search party ventures into the treacherous jungle to look for the pair. Suspicions focus on Ethan Rom (guest-star William Mapother), who, it was recently discovered, was not a passenger on the doomed flight. Jack battles inner demons relating to his father, while Boone and Locke discover another island mystery.
Jack, Kate and Sawyer fight over possession of a newly discovered locked metal briefcase which might contain insights into Kate's mysterious past. Meanwhile, Sayid asks a reluctant Shannon to translate notes he took from the French woman. A rising tide threatens to engulf the fuselage and the entire beach encampment, and Rose and a grieving Charlie tentatively bond over Claire's baffling kidnapping.
