Now, here is an interesting little theory I came up with by accident.
A lot of people have misunderstood why bloggers are asking "what happened when MiB entered the cave?" This is not because we want details of the physical, chemical and biological transformation process by which MiB went in, and Black Smoke came out, but rather of the significance of the event. There are two main interpretations:
- The Black Smoke was a pre-existing entity, biding its time until an opportunity arose. MiB's body (alive or dead) represented that opportunity, and the entity secured its release, and has been forever afterwards pretending to be Jacob's brother.
- Whatever happened in the cave, the Black Smoke was created by sending MiB into there, and the Black Smoke is simply the essence of MiB, which, over time, has grown in anger and malice.
The distinction is important, if only because (1) places the Black Smoke as a creature of total malevolence, with no hope of redemption; if (2), then as the Black Smoke was once a man, there is still hope and the smoke could be redeemed. It is the distinction between the irredeemable (1), and the redeemable (2).
The Smoke says it wants to go home. Jack accepts from Jacob the task of stopping it. If (1) is correct, then "going home", is a ruse, and is simply the means to an end, in which the Black Smoke will destroy mankind. If (2) is correct, then "going home" is an end in itself, and the Black Smoke simply has has enough of the island, and wants to leave.
"Let it go, Jack!"
... make your own mind up.