Kate and Sawyer discover a briefcase and the race begins to win ownership of it. Charlie is still depressed over Claire, and is given a sharp talking to by Rose.
Sawyer believes that a boar is harassing him. So he and Kate go to find it. They bond on the journey. They run into Locke, who tells them a story that seems to mean something to Sawyer.
When Hurley becomes obsessed with the French woman and heads into the jungle to find her, Jack, Sayid and Charlie have no choice but to follow. Meanwhile, Locke asks Claire to help build a mysterious item.
Claire goes into labor while a helpless Charlie goes into panic mode. Meanwhile Locke is missing, Jack tends to a wounded Boone and Sayid presents Shannon with a romantic surprise.
After burying one of their own, tempers flare as the castaways' suspicions of each other grow -- and an unlikely survivor vows revenge. Meanwhile, Claire and Charlie struggle to calm her newborn.
Jack suspects foul play when Michael becomes violently ill while building the raft. Meanwhile a secret from Kate's past is revealed, the mysterious hatch is shown to a few of the survivors, and Walt gives Locke a warning.
The castaways on the raft are surprised at sea by something unexpected. Meanwhile, remaining islanders attempt to blow open the hatch, and a visitor to the encampment might be a threat to Claire's infant son.
Jack, Locke and Kate learn more secrets about the hatch. Meanwhile, after being beaten and taken captive, Sawyer, Michael and Jin wonder if their captors are fellow survivors or the dreaded "Others."
Forty-eight days ago, the tail section of Flight 815 crashes. The survivors struggle to live when some other people on the island continue to kidnap some of them.
Kate's original crime that started her life on the run is revealed. Meanwhile, the survivors lay one of their own to rest, Kate sleeplessly watches over a feverish Sawyer, and Mr. Eko has a surprise for Locke regarding the hatch.