Contains spoilers for this episode and earlier episodes.
Kate emerges from the ventilation system and strikes Desmond during the hatch standoff. His gun fires and damages the computer, causing him to panic about the countdown. He explains that he has been entering a numerical code every 108 minutes and claims that failing to do so will bring catastrophe. Jack and Locke watch an orientation film that identifies the compound as the Swan station, part of the Dharma Initiative. The film describes an earlier incident and instructs its viewers to continue the procedure. Jack suspects an experiment, while Locke takes the warning seriously. Desmond abandons the damaged equipment and flees, with Jack following him into the jungle.
Flashbacks show Locke meeting Helen at a support group after his father's betrayal. Their relationship develops, but Locke repeatedly visits his father's house despite promising to stop. Helen challenges him to move forward with her instead of remaining consumed by what happened. On the island, Jack acknowledges his earlier meeting with Desmond and tells him that he married Sarah, though the marriage ended. Sayid repairs the computer, and Jack eventually presses the button before the countdown expires. Across the island, Michael, Jin and Sawyer are beaten and held in a pit. Ana Lucia joins them, claiming to be another crash survivor. When Sawyer describes his plan to shoot their guard, she takes his gun and reveals that she is working with their captors.