This music accompanies a rather important scene in the season 3 episode of LOST called "The Man Behind the Curtain." It's one of my favorite episodes, and one of my favorite scenes in the episode. Don't be fooled by the gentle music in the middle--the scene is quite brutal. But I won't ruin it for anyone who's somehow managed to not see it yet. (Go to abc.com and watch it now! Er, watch the earlier episodes first, though.)
Anyways, nearly all of this cue is based on the theme Michael Giacchino wrote for the Others. It later became more of a theme for Benjamin Linus himself, as is the case in this scene. Normally, it's heard in the sinister and insidious sorts of statements you hear at the beginning and end of this recording. But starting with this episode, Giacchino also incorporates this touching variation that uses chords and another phrase or two to give off a very different vibe.
I arranged this by ear, based on the soundtrack and on the episode. You'll notice that I've adhered to the structure of the edited version in the episode, not the original structure heard on the soundtrack. In a rare turn of events, I actually prefer the edited version. =P It's more dramatic.
Enjoy, and let me know how I can improve!