Contains spoilers for this episode and earlier episodes.
Flashbacks show Boone travelling to Sydney after Shannon calls about her boyfriend Bryan's violence. Boone offers money to make Bryan leave, then learns that the supposed rescue was a scheme to obtain cash from him. Bryan takes the payment for himself. Shannon later arrives at Boone's hotel, drunk and distressed, and acknowledges his attraction to her. The stepsiblings sleep together before she insists that they return to their old relationship when they reach Los Angeles.
On the island, Boone resents Shannon's growing closeness to Sayid while helping Locke uncover a sealed hatch. He wants to tell her about their discovery, but Locke strikes him, ties him up and applies a paste to his wound. Boone hears Shannon screaming and frees himself to reach her. He believes they are fleeing the jungle creature together, then finds her apparently dying beside the water after it takes her from him.
Boone returns to camp and attacks Locke, blaming him for Shannon's death. Locke points out that Shannon is alive nearby and explains that the paste caused Boone to experience a vision. The pursuit and death were not actual events. Asked how he felt when he thought she had died, Boone admits he was relieved. Locke invites him to return to their work, and Boone follows him into the jungle, continuing their partnership around the unopened hatch.