This thought has been whirling around in my mind ever since I re-watched seasons 4 & 5 of LOST, and last week’s ep [Lighthouse] seemingly added another layer of affirmation. Since I wrote out my theory in a rant-worthy fashion on Google Buzz, during a discussion with @snarkle, I thought I may as well regurgitate it here.

Note: Smokey = Smoke Monster = MiB = Fake Locke = Flocke

Jacob’s Cabin/Circle of ash 
The cicle of ash around Jacob’s Cabin is an anti-Smokey mechanism. So, if Smokey’s roaming around the island, the on-island Christian Shephard inside that cabin John Locke sees surely cannot be Smokey. 

Claire/Lighthouse

Two quotes from “Lighthouse” sum things up, where Claire seems to make a clear distinction between her father [on-island Christian Shephard] and her friend.

“First my father told me, and then my friend told me” – Claire, when explaining to Jin how she’s so sure The Others have her baby

“That’s not John. This is my friend” – Claire, at the end of the episode when Flocke walks into her camp

What ruins the theory

There’s just one scene that’s stuck with me that ruins this theory. In “Something Nice Back Home”, Jack, working at St. Sebastian hospital hears the smoke alarm beeping and then sees Christian Shephard. At the time, that smoke alarm going off meant only one thing to me, which sort of ruins the theory that they’re separate entities. Unless… there are two Smoke Monsters…

Smokey Candidates

If the two are separate entites, what does it mean? It’s only fair that if Jacob has his candidates, Smokey should be allowed to have some of his own too. Is this what Christian Shephard and Claire Littleton are?

We haven’t seen Claire doing too much for Smokey, but Christian certainly has:

• Led Claire away from Aaron [to Smokey?]
• Seen sitting with Claire in Jacob’s Cabin
• Crucial in making John Locke believe he had to sacrifice himself, off-island, which I believe was needed for Smokey to take his form when he returned in the coffin
• Told Sun to wait for John Locke [who was Flocke at this point]

UPDATE:

In retrospect, all I needed to say was, Smokey cannot leave The Island. Jack seeing Christian Shephard in “Something Nice Back Home” either disproves this fact [of which a 0% chance exists], or this is a plot hole.