Locke hasn't had much to do character wise this season. The writers clearly want to keep what happened to those still on the island a secret so most of the cast, whose back stories have been explored well enough, didn't get much in the way of centric episodes (it's odd this season didn't do a Sawyer episode). This episode is the closest this season's gotten to a traditional flashback episode. Locke's role on the island is about to become very important. He's been claimed as the new leader and protector of the island and as the episode ends, the enemy has touched down on its soil. So it's a good choice to explain how Locke got there, which goes back to beyond his birth.
This episode serves as a worthy companion piece to "The Man Behind the Curtain" in many ways. It revisits several settings and elements like the cabin, the mass grave, Jacob and Horace's Sisyphus-esque cameo. They both deal with how the respective character gained control as protector of the island, including premature birth around the same stage in the pregnancy, losing a mother named Emily (albeit in different ways) and encounters with Richard Alpert involving some element of island mythology they wouldn't know otherwise, in Locke's case his picture with a man in peril an a pillar of smoke. Some suspect that Locke's flashbacks at 5 and 16 coincide with Ben's birth and arrival on the island. The flashbacks also feature another actor playing the character at greater length than other episodes, where it'll be relegated to the prologue or first act. Highlighting the similarities fits this episode, as Locke begins to have some sort of respect for Ben.
In the "Meet Kevin Johnson" review, I remarked how the island keeping people alive wasn't that far fetched an idea considering how other characters have been spared from harm by some providence (Michael himself was spared a gunshot to the head this week). This couldn't be more appropriate for Locke. Born three months premature to a mother who just got hit by a car, he warded off illness and grew up otherwise healthy and that doesn't even compute surviving an eight-story fall with only a broken back or a plane crash that should've killed everyone on board.
Following Alex's murder, Ben is showing something we've never seen him show before, resignation. Of course, losing his daughter is a big contributor to this sleepwalking, but the big piece is that he feels his time on the island as its protector is over. It's hard to believe that Ben has become sympathetic to some degree. The moment where Hurley shares his candy bar (which looked like a brand name and not Dharma) comes off as oddly touching. With that, we have to consider his future where he has a renewed resolve in the war between himself and Widmore and what happens between now and the moment he arrives in the Sahara that reinvigorates him.
Horace's remark that he's been dead for twelve years has generated a lot of discussion about contradicting the timeline or even retcon. That statement would place The Purge at 1992, four years after Rousseau arrived on the island. Shortly after she gave birth Alex was taken. So how exactly was Ben a father to Alex for four years if he had to maintain a façade of loyalty to Dharma? It's possible Horace isn't a reliable source of information as he is a vision, but hopefully there will be an explanation in a future Ben episode.
With the cancellation of "Cane", Nestor Carbonell is free to return as Richard Alpert, and he plays an interesting part in this episode. Alpert, who resembles John Hamm from "Mad Men" in this episode, once again shows his lack of aging appearing in young Locke's life after he's born and at five years old. This also has been accused of retcon with Locke not remembering him when he first encountered him on the island last season. Obviously he wouldn't remember him after birth (the flashbacks serving narrative function). As for when he picked the wrong item of the six, would it be realistic for someone to remember what a guy he met for two minutes forty years earlier looked like?
In the DVD commentary for "The Man Behind the Curtain", Damon Lindelof compares Alpert's role in The Others' society to the Panchen Lama, second to the Dalai Lama who finds what they believe is the reincarnation of the Dalai Lama when the old one dies. This is recalled when Alpert asks Locke to pick what item "belongs" to him, which is similar to a well known test to determine the new Lama. If the previous leader(s) did die(d), that adds credence to Locke's flashbacks at 5 and 16 to take place parallel to Ben's birth and arrival on the island. They also reference X-Men with Alpert's description of a school for people who are "extremely special".
It's interesting that The Others' front, Mittelos (in this episode Laboratories), tried to recruit Locke as a teenager. Perhaps Juliet was picked to come to the island for something other than her expertise in fertility.
Then we have Abaddon appear as an orderly at Locke's rehab facility planting the idea of going on a walkabout, the thing that would get him to Sydney and eventually the island. Now it may be that Abaddon and Alpert are their respective opposite. Widmore, suspecting Locke was the heir apparent for the island's throne, sent Abaddon to put the gears in motion that would take him there in hopes that it would give him access Ben would never allow. This may foreshadow his return in the finale.
Christian appearing in the cabin, claiming to speak on Jacob's behalf is one of the trippier moments of the episode. Why Jacob wouldn't appear directly could point towards more manipulation and "the island's conning Locke" theory that was popular in the second season. There had to be something with Jack's father's body not being in the casket when he found it back in the first season and now we're seeing the beginnings of that answer.
Claire, acting a little under the influence, doesn't seem that concerned with Aaron (some have criticized her for not caring more for Charlie this season as well). Assuming she isn't dead, it would be a fair assumption to believe that Christian (Jacob) took Claire to the cabin for safekeeping as the mercenaries prepare to invade the island. Since the cabin doesn't have a fixed location (except when Locke finds that map), it's safe to protect her so she can raise Aaron when the dust settles. However, why is Aaron, under the care of Sawyer and Miles heading back to the beach, "where he's supposed to be"? This may refer to a temporary caretaker and they failed to consider someone else taking him off the island in the battle.
The idea that the island can move has been around for a while, at least as far back as the introduction of Eko's plane. There's no way a Beechcraft 18 could make it from Nigeria to the island. The mobility of the island may explain how the Real Henry Gale's balloon got to the island as well. Moving the island may be through time as well as/instead of space, which adds another layer of complications to the mix.
Jacob's decision that the island needs to be moved could explain how only the Oceanic Six make it off the island, as well as Ben's appearance in the desert wearing a parka with the same Dharma logo on the top secret plans Keamy claims will help them locate Ben. It all ties to what many believe is The Orchid Station. Ben and presumably Widmore know that station is where they need to be to move the island. That place may be cold or the island may move somewhere colder shortly before Ben jumps to the Sahara. The Oceanic Six may be the first six people the Zodiac raft picked up before the island moves, where the castaways can't find it on a second run or as they speed away from the island.
Gault, the captain Michael warned Sayid and Desmond couldn't trust, turns out to be not more than a patsy. Keamy, who has become a formidable antagonist, walks all over Gault and is the only one of the two who had knowledge of the plan to "torch the island". Gault may have been hired simply because he can command a ship.
A lot of emphasis is made on the device strapped to Keamy's arm, so much that he thought that was enough of a deal to get Gault to stand down (or perhaps part of a con to distract Gault long enough to get a gun and kill him). An initial theory is that it's some heart rate monitor, where if it goes too low it'll set off some explosives, likely on the freighter. Whatever it is, it'll likely play a big part in the finale.
One major stupid moment occurs when Gault, who has Keamy at gunpoint, turns away to ask what the device strapped to Keamy's arm is. This is the guy who slit an innocent man's throat and threw his body overboard to prove for point a minute earlier and he's going to look away for a second? This was an ultimate contrivance where they had an otherwise reasonable character do something stupid so the story could reach a certain point.
Desmond staying on the freighter may spell his doom, but it also may be why he isn't one of the Oceanic Six. I'm reluctant to say Keamy's device causes the freighter to explode, as it would be too similar to the raft pack left to die by The Others in "Exodus Part 3". Some suspect in a twist of cruel irony, Penelope finds herself on the island shortly before Locke "moves" the island, reversing the dynamic. It would be interesting because Desmond's cowardice was partially responsible for both. That may be interesting, albeit tough since Sonya Walger has two other shows to juggle.
Obviously the confrontation between the mercenaries and the castaways isn't going to end well. Knowing the future, Jack misreading Frank's warning of the satellite phone as a method to find Keamy rather than avoid him, will likely prove a fatal mistake. That makes Sawyer and/or Sayid's arrival to warn them of their true intention likely to happen too late in the proceedings for Jack and company to do anything about it.
This episode does a good job of giving Locke, who hasn't had as much to do this season, a major spot in the storyline as the showdown between the castaways as a whole and the mercenaries on the freighter draws close. This season has so far hit most of the right marks and the road to the finale is no exception. The tension is high and with only a few people guaranteed safe and major answers on the horizon, it looks like the finale will easily deliver on many of the promises this season has made.