Contains spoilers for this episode and earlier episodes.
Michael objects to Locke teaching Walt to throw a knife and insists that his son help gather materials for a raft. Their argument worsens when Walt rejects Michael's authority, and Michael burns his comic book. Walt runs away with Vincent. Michael initially blames Locke, but the two men search together when they realize Walt is missing. They find him trapped by a polar bear and cooperate to drive it away and rescue him.
Flashbacks show Susan taking the infant Walt to Amsterdam for work, separating him from Michael. After learning that she is involved with Brian, Michael steps into traffic and is hit by a car. During his recovery, Susan asks him to let Brian adopt Walt. Years later, Brian reports Susan's death and wants Michael to take the boy back. He admits that he never truly wanted to be Walt's father and finds the unusual things happening around him frightening.
Michael travels to Sydney to collect Walt and Vincent, discovering that Susan withheld the letters he sent his son. On the island, he shows those letters to Walt, giving them something to share after their confrontation and the rescue. Charlie separately retrieves Claire's diary and finds a reference to a black rock, which may offer a clue to her location. While searching for Vincent, Locke and Boone instead encounter Claire herself, stumbling out of the jungle.