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.
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.
Claire launches a plan to use migratory birds to send a message, but she doesn’t understand why Desmond keeps sabotaging it. Elsewhere on the island, Sayid, Locke and Kate scale The Others’ protective perimeter and discover their camp.
Ben, Locke, and Hurley go to The Orchid, but Keamy and his men beat them there. Jack and Kate go after the helicopter, and are later joined by Sawyer. Sayid comes back to the island with a rescue boat, and then goes after them too.
Juliet exposes Sun’s pre-island affair to Jin so that they won’t defect to Locke’s camp. Sayid and Desmond meet the ship’s captain and discover that Michael is working on the boat.
Sayid negotiates a deal with Locke to hand over Charlotte from the “rescue team,” so that he can get on their helicopter and reach their ship. Kate joins Sayid for the mission, but she decides to stay behind with Sawyer.