Jacob=Alvar Hanso, Ben & Locke=brothers

[pugsy]

A lot of people think the freeze-frame picture of Jacob in the cabin looked like Locke with a wig, or an older version of Locke himself, but I'm going with Alvar Hanso.

Hanso switched gears and started pursuing more lofty goals, so Mittlewerk is holding him hostage in some form of limbo. Ben and the Others/Hostiles are in on it and helping Mittlewerk to use the island for other means. Also, the cabin could have been Hanso's home while on the island.

Now I'm really going to go way out there....Given the similarities between Ben & Locke with their mother's names, patricide, Locke gave away one kidney and Ben had his cut by Jack on the operating table, etc, what about the possibility that they are brothers? And, their real father is.......Christian Shepherd! (Just kidding, that's an inside joke to those who've read some of my other posts about Christian's womanizing). No, their real dad is.......Alvar Hanso! Hence, they are the only ones who can hear him.