Mr. Eko enlists Locke to help find a secret location he believes houses answers to the island’s mysteries. Meanwhile, Jack, Sawyer, and Kate struggle to cope with the horrific situation in the hatch following the escape of “Other” Henry Gale, and of the shooting deaths of Ana-Lucia and Libby, unaware that it was Michael who is responsible.
Jack and Kate bring an exhausted Michael back to camp where he has news about “The Others”. Meanwhile, Ana Lucia attempts to get the prisoner, Henry Gale to confess to being a spy for the Others, and he attempts to kill her. Also, Hurley plans a surprise date for Libby.
When the hatch suddenly takes on a life of its own, Locke is trapped alone in the bunker and is forced to enlist the help of an unlikely ally: the captive Henry Gale to try to free him. Meanwhile, Jack faces off against Sawyer in a series of card games for supplies. Also, Ana Lucia, Sayid and Charlie find out the truth about Henry in the jungle.
When Sun comes to the realization that she might be pregnant, she struggles on whether to tell Jin about the situation. After no success from Jack or Sayid, Ana-Lucia is called in by Locke to interrogate the prisoner, Henry Gale, to get more information out of him about how he arrived on the island. Ana-Lucia, Sayid, and Charlie then set out into the jungle to try and confirm Henry’s story.
Survivors fear that “The Others” may have returned when Sun is injured during a failed kidnapping attempt. Meanwhile, Sawyer is an amused, but highly interested, bystander when tension escalates between Jack, Locke, Kate and Ana Lucia over control of the hatch computer, and the storage of the weapons.
Sawyer’s wound becomes life-threatening as he, Michael and Jin make their way through the interior of the island with the tail section survivors, Ana-Lucia, Mr. Eko, Bernard, Libby, and flight attendant Cindy. Meanwhile, Shannon is once again haunted by visions of Walt, but she cannot convince a skeptic Sayid that her visions are real. More of Shannon’s background story shows her difficult relationship with her late half-brother Boone and further detailing how her step-mother financially cut her off after the death of their father. Also, Charlie becomes jealous of Locke’s interest in Claire, while Locke learns that Charlie took a heroin stuffed porcelain statue from the Beechwood plane wreck.