So they play the game, and there's some minor squabbling between Jacob and Jacob's brother, and eventually Jacob bails and tells Mother about Brother's game. (I can already tell I will get tired of typing "Jacob's mother" and "Jacob's brother, whose name is withheld for possibly foolish reasons, likely because the show's creators are confusing engaging mystery with pointless obfuscation." So let's just go with proper nouns for now.) Mother comes down to the beach and gets Brother to admit he found the gane, but she says she'd planted it for him to find. He's a bit disappointed, since he'd hoped the game had come from "across the sea," but Mother tells him there's nothing out there, and that the island is all there is. She also tells him that he and Jacob came from her, and she came from her own mother, who's now dead, but Brother doesn't understand the word. "What's dead?" he asks. "Something that you will never have to worry about," she replies.
Some time later, the boys are hunting a boar when they lose sight of it only to hear it speared by someone else. They hide and see a group of men in leather vests come up and start stripping the animal. Fleeing to tell Mother back home in their cave, she tells them they need to get away, since the men don't belong there while Mother and the boys are there "for a reason." That slip is all the motivation Brother needs to pester her to reveal this reason, so she submits. She blindfolds them and leads them through the jungle, telling them she knew the men were there but lied about to keep the boys safe. "They come, fight, destroy, corrupt, and it always ends the same," she says. These are the exact words spoken by the Enemy in last season's finale, "The Incident." Mother also tells the boys she's made it so they can never hurt each other.
They eventually arrive at what she calls "the reason we're here": a small stream flowing into a low cave mouth that's emanating a warm, golden light from somewhere far below. Mother says that men want to come take the light because a little piece of it exists in every man, making them want more. She says the men can't take it, but they can try, and they can put it out, but if the light goes out there, it goes out everywhere. She also tells the boys she can't protect the light forever, so one of them will eventually have to take over.
Later, the boys are playing Senet again as Brother riffs some more about how he gets to make the rules since he found it, and how Jacob can make his own rules for his own game later, which are you serious Damon and Carlton. Brother catches a glimpse of Claudia in the distance, though, but Jacob can't see her. Brother follows the vision into the woods, and Claudia says she wants to show him where he came from. She leads him across the island to a group of huts and tells him these are people who wrecked on island 13 years earlier, the day before Brother was born, and that she, Claudia, is his real mother. Brother at first bucks at the idea of being from "across the sea," where Claudia tells him there are "many things," but he eventually goes with it. That night, he gets Jacob and they sneak out of Mother's cave to head back to the huts, but Brother's announcement of Claudia's truth upsets Jacob, who launches at his brother and starts beating him before Mother appears and stops it. Brother says he's going with his newfound people so he can leave the island, but Mother tells him he won't be able to. Jacob stays with Mother as Brother leaves them behind. Next morning, Mother admits to Jacob she killed Claudia but did it so Jacob would "stay good." He asks why she loved Brother more, but she says it wasn't more, just different. Jacob agrees to stay with her for a while.
Cut to years later, with Jacob looking as he did when we first got to know him last season. He's working on the loom that Mother used when they were boys. He later heads down to the village to meet up for some Senet with Brother, now also grown into the early-middle-aged man we recognize. It's been 30 years since Brother moved out, and in that time, he's observed that the people he lives with are greedy, corrupt, lazy little bastards, though he tells Jacob they're just means to an end. Jacob, who's been watching the group for years to see if Mother was right about them, then learns of Brother's plan when Brother throws a knife that's grabbed from the air and sent spinning to the brick wall of a nearby well. Brother says that "metal behaves strangely" at certain parts of the island, and it's in those places that he and the curious men he lives with have started digging. "This time, we found something," he says. They bicker again about how Brother wants to leave and Jacob wants to stay.
Jacob tells Mother that Brother has found a way off the island, so she journeys down to the dig site to find Brother working underground before a large stone wall. He tells her that he looked all over for the cave of golden light before realizing that he might be able to get to it by digging from above, and that he and his people have some "very interesting ideas" about what to do with it now that they've found some. He pries a stone from the wall to reveal golden light, a beam of which shines out to illuminate the giant wooden wheel he's built to install in the wall. Once attached to a system designed to channel water and light, the wheel can be turned and he'll be able to leave. She moves in to hug him goodbye, and I almost believed he'd try something on her when instead he just softens and hugs her like a boy with his mom. That's when Mother comes in for the reversal, telling him she's sorry as she screams and rushes him against the wall, knocking him out as his head hits a stone.
Mother rushes back to the cave to get Jacob and lead him to the golden light cave, telling him that his brother wanted to leave so now it's up to Jacob to protect the light. She pulls out a wine bottle (the one Jacob still has years later) and pours a drink while chanting over it, then passes the cup to Jacob. He's reluctant to take it, saying he knows that Brother was supposed to be the one chosen, but Mother tells him it was "always" supposed to be Jacob. He eventually drinks, and she says, "Now, you and I are the same." She warns him never to go down into the golden cave, though, saying he'll suffer a fate "worse than death."
The next morning, Brother wakes above ground to find the dig site filled in and the well destroyed. He sees smoke and runs to find the small hut village burned and
Owen and Beru the people slaughtered. He digs the Senet game from the wreckage and starts to seriously rage out. Meanwhile, Jacob and Mother are walking through the jungle ominously and not at all metaphorically talking about an impending storm. She sends him off for firewood while she returns to the cave to find it trashed. She sees the Senet game and opens it up to find one white stone and one black one. She's examining the black one when she's suddenly stabbed through the chest by Brother. She uses her last energy to tell him she kept him on the island only because she loved him, and then she thanks him, then dies. Even though he killed her, he's still a son who lost his mom, and he weeps for her. That's when Jacob comes home and sees what's happened, and flies at his brother, beating him up just like when they were kids.
Jacob drags the woozy Brother through the jungle to the cave of golden light, knocks him out one final time, and drops his body into the water, which ferries it down into the mouth of the cave. Brother gets sucked down underground at the back of the cave, which is when the wheels really come off the wagon on Craphole Island. A thundering rattle sounds just as the smoke monster erupts from the mouth of the cave, no longer glowing like before. The monster flies over Jacob's head and into the jungle and disappears. Jacob runs away and stops at a nearby stream, and just as Claudia did years before, he drinks some water before looking up and finding a surprise. This time it's the body of his brother, splayed out on rocks and branches not far downstream from where the water emerges from within the hillside. Jacob cries as he touches his brother and then lifts the corpse, carrying it home to his old cave.
Once there, he grabs the white and black stones from near his mother's body and slips them into the leather pouch that Jack and Kate will discover centuries later when they first explore the caves. He then lays the dead bodies next to each other in a raised enclave in one of the walls, pressing their hands together, and we get another brief cut to the first-season ep in which Locke dubs them "our very own Adam and Eve." Still weeping softly, Jacob says, "Goodbye, brother. Goodbye."
And that's that. Like I said up top, it was kind of a truth dump, and there's a lot of info to absorb and sort. For starters, I had no idea the whole "raised by another" thing that was such a big deal with Claire and Rousseau would have its roots in the way Jacob's mother had murdered his birth mother and taken him to be the island's guardian. But how did Mother get there? Either we will find out, or it will be just one of those things that's accepted as a blind premise, like, "Once upon a time there was a magical island with a crazy lady on it whose job it was to guard the source of all living good and evil."
What exactly happened to Brother when he got sucked into that cave? It seems like either (a) his presence set loose the smoke monster, which killed him and escaped, or (b) he became the smoke monster, having his soul and essence turned into a cloud while his body was discarded and sent down the falls. We didn't see what happened in the cave of golden light, but having your soul ripped out and turned into an evil cloud, or at least bonded with it, would definitely qualify as "worse than death." Both possibilities seem workable. Smokey can take the form of dead people, so maybe he killed Brother when the body went into the cave and now uses that form/personality as his default, like he did when we first saw him last season, when he and Jacob watched the Black Rock approach the island. We also know that the Enemy can take the thoughts and personality of the people it pretends to be, which is how it was able to discourse on John Locke's final private thoughts before his death. So if the monster already existed and just took Brother's form, it would stand to reason he got his feelings and ideas, as well. Then again, if Brother became the monster, that would go a long way toward clearing up the things MIB said to Claire a couple weeks back about having a "very disturbed" mother who caused him "growing pains." What do you think? Is the smoke monster Jacob's brother, or just a monster who pretends to be Brother to screw with Jacob's stability? (I like the former, because it's more tragic and [slightly] less complicated.)
Also, is there some other force on the island that just creates ghosts? Isabella for Richard; a young boy for the Man in Black; Claudia for Brother. Is this just one of those things that happens?
Still, it's interesting to see the origin of so much of what the show is about now. Increasingly, things like DHARMA feel less like full plots and more like off-shoots caused by the real struggle between Jacob and the monster over an island whose pockets of electromagnetic power can change or destroy the world as well as generally futz with the flow of time. DHARMA came for the power, and Jacob's people killed them and assimilated their few survivors, like Ben, who ousted Widmore from his leadership role in the Others. Ben and Widmore's battle is a mirror of that between Jacob and his brother in that there are rules governing who can kill whom, though how these rules were carried down and applied remains unclear. But it can't be an accident that Ben was healed as a boy in the Temple and that we've seen Sayid resurrected in a pool of lit water that bore a resemblance to the cave of golden light, right?
It's also interesting to note that Jacob and the Man in Black are at this point both fighting because they're trying to prove their mother wrong in different ways: MIB wants to escape to see the world across the sea, while Jacob wants to know that people have the capacity for a moral good that his mother said wasn't possible.
Oh yeah: Mother also spent a lot of time telling Brother that he was "special," a word that's applied to Desmond a lot, as well, but who knows where that will lead. We'll find out in a few hours.