It's rare that we get a title of an episode which seems so unambiguous. This episode is all about leaders, and who agrees to follow them. There are major shifts in power in this episode, some of them expected, some genuinely shocking. There are also a couple major shifts in whose willing to follow, and that's even more unnerving.
Jack has been willing to sit on the sidelines ever since they got back to the island, but now that he's heard Daniel's plan, he seems to accept it flat out as the reason why they're here. And if you look at it from a purely scientific point of view (like Jack would've before he came back to the island) we see why. There were 324 people on Oceanic 815 when it crashed. Of the original 71 survivors, less than a dozen are still alive. (We still don't know what happened to Bernard and Rose, or if Claire is still with us.) If the bomb goes up, all of these people will live. When I heard this option, it seemed like it was the only humane thing to do. But Jack isn't looking at it that way, at least not entirely. If he doesn't crash, he won't have to be put through the rigors of the island--- he won't have to watch patients die without any supplies, he won't be forced into a leadership role that takes a huge toll out of him, he won't have his sanity weighed upon by smoke monsters and buttons that need to be pushed every 108 minutes and appearances of his dead father, he won't give in to the addictions that plagued him when he returned --- he won't suffer the pain of having to lose Kate.
Kate takes this as a challenge, and will not go along with it. the difference between her and Jack is that she's not even hiding that she's looking at it from a personal point of view. She won't have loved Sawyer or Jack, she won't have the memories that she had with Aaron, she won't have the friendships she made--- and she's going to be cuffed to a marshal who most definitely wants to see her in prison for the rest of her life.
The only reason that they are being given a chance to make this decision in the first place is because of the actions of 40 year-old Eloise, who has come to the realization that she has shot her son, and as badly as Jack wants not to have come to the island, she wants a do-over as well. Perhaps this is the real reason she pushed Dan so hard--- she was trying to set up the very circumstances that would lead to this happening. Whatever the reason, she persuades Charles and Richard to follow through with this, and on their way they meet another familiar face--- Sayid, who's been hiding in the jungle for the last three days. He's not happy to learn that Kate saved Ben despite what he did, but he doesn't seem to need much persuasion to do it other wise. This isn't surprise. If this works, he might find Nadia, she might not be killed, and he won't be turned into a mindless assassin. But the realist in him must doubt this, because there is a moment when he says jokingly to Jack that "if it doesn't work, at least it'll put us out of our misery." And Sayid's life has by far been the most painful so far.
On the other side of the island, another kind of coup is taking place --- Radsinsky has just seized power from Horace, and is beating the hell out of James. James tries to hold firm, but as soon as they start wailing on Juliet, he gives in. Everything he's built over the last three years has turned to dust over the last three days, and now he wants to try and rebuild something with Juliet on the sub. We don't know if he'd ever go through with it (given how reluctant he was to leave the island before) but he seems genuinely repulsed by what's happening. He might even have gone through with it--- but then Kate is brought handcuffed on the sub with them. James tries to hold firm, but Juliet has completely broken down at the site of her. The moment when she appears on the sub is one of the most emotionally painful--- and we've just seen minutes of the two being beaten up.
Meanwhile, thirty years later, Locke walks up to Richard on the other side of the island, and Richard seems genuinely surprised to see him. Locke now demonstrates that he is truly the Chosen One, by telling Richard he has a job to do--- save himself. Somehow, we've arrived moments away from the second flash that we saw way back in the season premiere --- Locke lying near the plane, having been shot by Ethan in the first flash. He gives Richard clear instructions to say exactly what he said before. Most importantly, he makes sure that Ben is along for the ride, even though he's superfluous. Locke clearly just wanted to show to Ben that the island is talking to John in a way it never talked to him. (It's also interesting to know that when Ben sees the plane, he doesn't recognize it. Or he says he doesn't. Probably this is more fertilizer that he's always had.) Then Locke confronts Ben on something--- that's he never seen Jacob and never spoken to him. Ben is clearly so flustered by this that he owns up to it. But he seems to know (of course, there's a real good reason for that, but we won't learn it until... too late) and has a surety and confidence that he's never had before.
So Locke finally confronts Richard in a way he hasn't had a chance to, and demands to see Jacob. In doing so, he turns the Others into something that we've never really seen on the island --- a democracy. Well, it looks like one, but much as the Dharma Initiative behaved when they were deciding Sayid's fate, it seems to be forced coercion. Richard is clearly unsettled by all of this, which is telling. Both here and in 1977, the once unruffled Richard is starting to look more and more surprise as if this is something he's never seen before. We also learn that he serves as an adviser to the leader (Ben tells Sun that's it been for a very long time, but again stops short of telling us how long), but he answers to Jacob. This seems a little surprising considering how shocked Ben was when Locke first suggested that Richard could take him to Jacob, as if it had never happened before. Maybe there's more to this story that we haven't heard yet.
Locke then leads the Others on a mission to see Jacob. And it is there that we get the first sign that maybe the Locke we've seen isn't the same one we've known before he died. He tells Ben directly that he has no interest in helping Sun find her husband and getting reunited with his people--- a direct contradiction of what we saw when Locke went down into the well. Then he tells them that he has one specific mission--- to kill Jacob. Which startles Ben so much, he stops in his tracks. Why on earth would Locke want to kill a man he's only seen once? Has Locke come back wrong somehow? At the time I wasn't sure I believed what I heard, and now... oh boy.
So now it appears to be a race. Jack and Sayid are trying to detonate a bomb which will stop the crash from happening. But we know what H-bombs do, and there's a good chance it'll kill everybody on the island, if it doesn't evaporate it entirely. Locke seems determined to kill Jacob, and he's moving pretty damn fast too. Events may be taking thirty years apart, but does someone know that one has to predate the other? Richard tells Sun in the beginning of this episode that he saw their friends all die. Will this happen despite what Jack is planning, or because of it? A lot of our questions are going to get answered soon, but it seems sure that there will be blood. A lot of it.