So, it was with trepidation that I approached the sixth season, and in fact in the final two and a half hour movie, they never did play out the larger back-story. This post is aimed at exploring what was actually going on and whether, speculation aside, we had enough information to understand what it was that was going on. This will involve spoilers for the entire series. If you haven't watched the final seasons, I suggest you do, but go in expecting a non-reveal. I liked the last episode, but I felt the way I felt at the end of Donnie Darko: clearly someone knew where they wanted to go with this, but decided they didn't have the time, creative freedom or desire to follow through. In the case of DD, the story played out in supplemental materials on the Web. In the case of Lost, I think the creators simply don't want to explain what they feel they've sufficiently hinted at, for fear of losing the sense of mystery.
OK, so let's see if we can extract reason from this show. There is really only one unanswered question of merit: what is the island? The other questions ("what are the numbers," "why do pregnant women die, etc." are secondary to this central theme and may not have answers outside of fan speculation).
Jacob gives us a metaphorical answer to this question. He explains that the island is like a wine bottle, holding in some sort of evil using a cork. I think it's safe to say that Jacob has more information about this than most, but in order to explain what he meant, we need to look at the evidence that we've been shown:
- Whenever someone opens up a hole in the island to expose the "magnetic anomalies" something very bad happens involving a flash of light, the release of a large amount of destructive energy and some strange shifts in reality/time (including the removal of Desmond's clothes, the shifting of the 1970s group to the "present" and so on).
- It looks as if one such opening was created a very long time ago, and "stopped up" by a large stone "cork" in the cave where the light is seen.
- The smoke monster came out of the cave with the light when the Man in Black (MiB) was thrown in, but the MiB's body was later found, suggesting that he died.
- The smoke monster can assume the form of many of the people who have died on the island or have strong attachments to those who are there (e.g. Jack's father).
- When the stone cork is removed, the light is dulled to a reddish and darker hue and the island starts to crumble.
- When Jack goes down to get Desmond, at least one, possibly two skeletons are seen. Since we know the MiB's skeleton was in the cave where the Losties found refuge, this skeleton must belong to someone else.
- In the very old temple that appears to pre-date Jacob and the MiB, there is an icon showing the smoke monster. This means that the smoke monster has appeared before, prior to the MiB's death.
But there are cracks in this veneer. There's a killer, a drug abuser, a torturer and many other forms of unsavory characters among our band of "heroes," and they are all drawn back in to their personal unpleasantness. As the series progresses we find out more about The Others, and they're not quite the pure evil that we thought they were, either. Eventually, the two groups merge, but there's always a fragmentation and re-formation of the lines between sides. The island appears to bring out this fragmentation, and no matter how many interested parties are present, a duality emerges. "Us vs. them" appears to be the law of the island, but with each person responding on a personal level to the struggle and developing their own internal fight between darkness and light.
Finally, we meet Jacob and MiB. Now we have some clarity. Clearly Jacob is good personified and MiB is evil. Well... not quite. In fact, though MiB seems to have always tipped toward the darker side and Jacob toward the lighter, they're not that cut and dry. MiB is initially not vindictive and only attacks those who attack him first. In fact, it's Jacob who repeatedly beats MiB and eventually kills him, becoming a Cain-like figure. Their "mother" in turn, also struggled between her mission to defend the island and her ruthless and homicidal impulses. Again, we see this very personal struggle between darkness and light on the part of everyone on the island.
At every step, a layer of assumptions is removed and the dark stone/light stone analogy becomes more clouded. Is there a dark stone and a light stone, or are they purely internalized forces, vying for dominance within everyone?
Going back to our evidence, I believe that we can support this conclusion, which fits well with the character drama I've described, above:
The Island is a prison or containment vessel or battleground. We may never know which term best applies, but it is clear that there is a Light and a Darkness at play. Are they the same entity struggling internally as the island's inhabitants do or are there two entities in conflict? Again, we can't say, nor can we pinpoint the nature of the entities. They could be "gods" or "aliens" or some more general Gaimanesque manifestations of existential concepts. However, we know what it looks like when they interact with the world outside. When the "cork" of the island becomes weak it appears to manifest as a magnetic anomaly. When fully breached, time and other forces are bent in ways that Danial Faraday seems to have managed to understand to some extent, and which may even be directly responsible for the influence of the numbers (again, we could only speculate there, as we're never given enough information).
When Light seeps out through these small cracks it is able to influence the world by creating a protector (e.g. Jacob's "mother," Jacob, Jack and Hurley). When Darkness seeps out through the same cracks, it is able to manifest physically, but we see its limitations quite clearly. It seems to only be able to manifest by appropriating the souls of those who have died, and even then some proximity to one of the cracks appears to be required at first. This would explain why MiB became the smoke monster. It was his death near the cave of light that exposed him to Darkness's control and manifestation. It also explains the prior appearance of the smoke monster (as shown on the temple wall) and the resulting skeleton in the cave of light. This also implies that the whole cycle has played out before, culminating in the death of the smoke monster's vessel.
These breaches, however, are quite small. When they are pried open for short periods (e.g. by the wheel) the forces released can move the island and send people into different time periods, but actually opening a crack and leaving it that way would effect the escape of Darkness into the world (the smoke monster being just a sliver of its power, reliant on the soul which it infests like a parasite). Interestingly, though, it would also release Light which appears to be equally trapped, though how voluntary this is, or if they're the same entity is still unknown. The result could be Armageddon or some equivalent conflagration between the two.
So, the Island is a prison, capable of holding two beings (or one) whose attenuated power is capable of downing airplanes, shifting time and bringing dozens of people into interpersonal and internal conflict. Just imagine how truly awful it would be should that cork ever give way entirely. One day, I imagine someone like Faraday will have to come up with a way to re-build these soft-spots and shore up these weak spots in the island's containment. Until then, it will continue to fall on the shoulders of the protector to keep the damage to a minimum.
One interesting bit of hint at the singular or dual nature of Light and Darkness is the way in which the island responds to the death of their servants. When Jacob dies, it appears to lock MiB into Locke's form. This might suggest a more substantial connection between the two, and again we might be seeing an internal struggle playing out rather than the jailer / prisoner relationship.