In my March 4, 2010 post, I found a third child in the temple courtyard, standing beside Cindy who was guarding Emma and Zach. I have come to the conclusion that that third child was an apparition, probably of a young Sayid, after Sayid had been totally consumed by the darkness caused by the infection.
I make this conclusion based on the fact that the third child is not with Flocke's followers in the jungle. If Cindy put it upon herself to protect all the children, she would have protected the third child and they all would have left the temple together. Only children are Emma and Zach, for whom Flocke individually comforts (see above picture).
There is something inconsistent about the rules of death on the island. Jacob's body, which appeared human form with blood, was killed and burned to ashes. When Dharma buried its dead by fire, it was assumed that it so the Others or some entity could not take the body as a ghost or vessel. Yet, ghost Jacob still roams the island, probably in two forms: his ghost self and the blond jungle boy that Flocke and Sawyer ran into on the way to the cave. Can death divide one's soul into a good soul (a child) and a bad soul (an adult)?
