Michael scans the jungle, looking for Walt. He runs into Hurley and Jack, who haven't seen him. Michael sighs, frustrated, but continues on. Hurley says that Michael seems to hate being a father. But in the FLASHBACK, Michael is clearly thrilled about becoming a father and wants the best for his soon to be born son. As he and his girlfriend Susan shop for cribs, Michael tells Susan that he plans on doing some construction for extra money while she finishes law school. Susan is concerned about Michael giving up his art, but Michael insists that he can go back to that later. Right now, they have to prepare for baby "Walt" - named for Michael's father. Susan agrees, but wants to give Walt her last name - they aren't married yet, after all. And off their playful banter we ...
...return to the jungle, where Locke teaches Walt how to throw a knife as Boone looks on. Walt misses the tree several times, but Locke encourages him and tells him to picture success in his minds eye. Walt throws the knife a final time and hits his mark, amazing Boone and impressing Locke. Michael comes upon this scene and sends Walt back to camp, furious with Locke about letting his boy play with knives. The discussion gets heated when Boone suddenly lunges at Michael to protect Locke. They wrestle on the ground until Locke breaks them up. Locke explains that Walt is a special child who should be treated like an adult and allowed to realize his full potential. Michael orders Locke to stay away from his son.
We FLASHBACK to baby Walt, as Michael and Susan argue over him. Susan tells Michael about a huge job opportunity in Amsterdam and that she plans on taking Walt with her - she and Michael need some time apart. When Michael refuses to let Walt go with her, Susan calls his bluff - she can provide better for Walt and a court would certainly side with the child's mother. Michael looks down at his son, heartbroken.
On the island, Sun approaches Michael as he sits by a camp fire, watching Walt sleep. Michael admits that while he doesn't really know how to be a father, he knows it wouldn't be a good thing for his son to grow up on the island. Determined, he heads out to talk to Jack and Sayid about building a raft. When Jack and Sayid scoff at the idea, Michael takes the project as his own. He finds Walt reading through a familiar comic book - the one with the polar bear from the first episode - and enlists his help.
We FLASHBACK to Michael, at a pay-phone, begging to speak with Walt. He can hear a man's voice in the background and learns that Susan has been seeing her boss, Brian. Michael threatens to come to Amsterdam to get his son. He slams down the phone down and charges across the street when he's suddenly mowed down by a passing car.
Back on the island, Charlie searches through Claire's things, looking for clues and some sort of comfort and finds that her diary is missing. Kate leads Charlie to Sawyer, sure that's where they'll find it. But Sawyer doesn't give anything up without a fight and teases Charlie about the diary, knowing he's curious as to what Claire wrote about him. Charlie finally slugs him, grabs the diary and storms off. Only then does Sawyer admit to Kate that he hadn't gotten around to actually reading it.
Walt and Michael continue to scavenge for materials to build the raft - metal, tubes, cushions, plastic and tarp. When Walt spots Locke and Boone heading back toward the caves, he tells Michael he's going to get some water so that he can secretly follow them. As Locke and Boone return to camp, Shannon intercepts her brother, questioning why he and Locke haven't scored any boar on their hunts. She suggests Boone's time would be better spent if he came with her to help Michael on the raft. But the dynamic between them has clearly shifted and Boone flatly refuses the invitation. Meanwhile, Locke tells Walt to respect his father's wishes and not come around anymore. Michael drops in on them, incredulous at seeing Locke with his son again. Locke explains that he told Walt he wouldn't be spending any more time with him and offers Michael a mechanical pencil as a peace offering. Michael won't accept it and tells Locke that if he catches him with his son again, he'll kill him. Walt calls his father a jerk for sending Locke away and for not being around when he was growing up - "You only showed up when mom died. You're not my father." And though we can see this stings, Michael tells Walt that he's going to have to learn to listen to him. He orders Walt to stay put and tosses his comic book into the fire.
We FLASHBACK to a hospital room, where we find Michael, in a wheelchair, post accident, working on a detailed drawing. He tells the nurse that he's making a card for his sons 2nd birthday. Susan shows up, concerned that she hasn't heard from him in two months. Michael is disappointed that she didn't bring Walt, but happy to see her nonetheless. When Susan offers to pay all of Michael's medical costs, he intuits that she has something up her sleeve. Susan reveals that she and Brian plan to move to Italy and that Brian wants to adopt Walt. She tells Michael to consider what's really best for Walt over his feelings.
Back on the island, Hurley tells Michael that Walt and the dog took off. Michael heads straight for Locke, who insists that he doesn't know where Walt is. Off Michael's concerned look, Locke volunteers to help find him. In the jungle, Walt and Vincent are startled by a noise. Vincent breaks free from his leash and Walt gives chase.
We FLASHBACK to Walt, staring at Vincent as Susan and Brian discuss their day's work. When Walt interrupts them, Susan tells him to do his homework. But Walt says that he needs help with his report on birds of Australia. Susan suddenly feels sick, drawing focus away from Walt. And as Walt continues to call out for attention, as kids often do, a bird crashes into the sliding glass door that leads into their living room. Brian looks down at Walt, a little freaked over this odd occurrence.
Back in the jungle, Walt searches for Vincent, when he's startled by another noise. We FLASHBACK to Michael's apartment this time. He opens his front door to find Brian at his doorstep with bad news - Susan is dead. Brian confesses that he doesn't want to be a father - he adopted Walt because Susan wanted it. He offers Michael plane tickets and money. And though Michael would like nothing more, he puts Walt's best interests first and says that Walt needs Brian now - he is the only father Walt really knows. But Brian claims that he can't take care of Walt and hints that there is something "different" about the boy.
On the island, Michael and Locke come across Vincent's leash and hear Walt cry for help. We FLASHBACK to Australia, where Michael has come for Walt. A nanny tells him that Walt will be home shortly and gives him a box filled with unopened cards and letters - everything Michael has sent his son over the last eight years.
In the jungle, Walt finds himself trapped inside the vines of a Banyan tree with a giant polar bear lurking outside. We FLASHBACK a final time to the same house in Australia. Walt returns from school and finds Michael in his living room. But the two are complete strangers - Walt doesn't even recognize his own father until Michael ID's himself as such. Michael tells Walt he's going to take care of him now and tries to comfort him by using the dog. But Walt informs Michael that Vincent is Brian's dog. Michael tells Walt that Brian said he could have Vincent.
Still in danger, Walt calls for his Dad. Michael and Locke come upon the Banyan tree and walk a tightrope of vines to reach Walt. Seeing that the polar bear is on attack, Locke throws Michael a knife, which Michael drops down to Walt. Walt uses the knife to fend off the polar bear, allowing Michael to make his way down to Walt. Michael wraps some vines around his son's waist and Locke pulls Walt to safety. The bear returns and paws at Michael, who finally plunges the knife into the bear's neck, injuring it and driving it away. Walt worries about Vincent, but Locke reminds him that the dog returned once and assures him that it will return again. Michael gives Locke an appreciative smile.
Later, at a campfire, Michael is finally able to share his cards and letters with Walt who is surprised to learn that his father wrote him and confused that his mother never gave them to him. Michael tells Walt that she saved them because she must have wanted him to have them someday - and that someday is now. Meanwhile, Charlie finally gives in and reads Claire's diary. He finds some entries pertaining to him and reads that he made Claire feel safe. He also finds some entries pertaining to a dream about a 'black rock.' Charlie takes this information to Sayid, who confirms the mention of a 'black rock' in the French woman's paper. They speculate that this may be where they will find Claire - but not in the middle of the night. And out in the jungle, Locke and Boone search for Vincent when they see something rustling through the leaves. Concerned that it may not be the dog, Locke pulls his knife - but it's Claire who emerges from the bushes, dazed and confused, but still alive…