So I'm watching for a third time and Jacks Grandpa says "Next time I run away no one will find me." And he has just the items that Jack needs. Could gramps know about the Island also?
Personally I don't know. It's very plausible. Ties in with the whole John
vibe of the episode (those who believe in him will not die in a plane crash but instead will have everlasting life on The Island
), and indeed in reference to "his only son" Christian (whom some have thought could represent The Messiah, what with the whole resurrection thing and stuffs) and to Jack's belief issues in this episode too.