I'm purposely writing this before I take a look at other comments, theories and speculation. I want to enter my initial thoughts, without being lead astray by others. :)
First, the flash sideways only really seemed integral to the plot in three ways: (1) obviously, we see that Jack now has a son. Jack is still divorced, but the son is a major difference. (2) For any that didn't catch it, Jack had his appendix taken out when he was young in the flash sideways timeline. We'll remember that he had appendicitis on the island (in season 4?). So the difference in the timeline is obviously far more than just not crashing; something changed in Jack's life even back when he was so young. Also, this clues us in that Jack is even thinking about that... he still has some connection with the island in our original timeline. (3) Finally, he meets Dogen, who also has a son. Little more than "interesting" right now, I think.
But I loved the scene where Jack had a talk with his son at the bike rack. If I wasn't so tired and out of sorts last night, I'm sure I would have cried. But enough about that, what makes this wow? Reveals, not necessarily in order, and theories.
Reveal 1: The Temple is not safe. I don't know about you, but I'll have a tendency to believe Jacob at this point. But that begs the question, why does everyone else think the Temple is the safest place? Even Ilana, who knows Jacob. Theory: Jacob's presence (somehow) kept MiB from entering the Temple (he could only go underneath), so while everyone else is still caught up in the old belief that the Temple is the safest place on the island (it previously was), now that Jacob is dead he knows it's not, because MiB is coming.
Reveal 2: Dogen's not as "in charge" as we thought. Candidates "can do whatever they want". Theory: Candidates are the "variables" and they're what the whole argument between MiB and Jacob is all about. They're choices (or destiny) and the eventual outcome.
Reveal 3: Claire. And she recognizes Locke as "her friend" that's been helping her. I think we can lay to rest here that MiB is pretty bad. It seems like he's been nurturing Claire and her anger and killing rage. No doubt he's the one that lied to her and told her that the Others have Aaron. It seems like there's a little of the old Claire in there somewhere, since she saved Jin, but I don't blame Jin for being scared out of his mind. MiB recruits: Claire, Sawyer, and Jin. Jin, though, is obviously just playing along at this time so he doesn't get slaughtered. Locke showed up, so where was Sawyer? Just outside the tent? I suppose we'll see next episode.
Reveal 4: Obviously the biggest reveal yet. We get another insight into the numbers: degrees around a circle. None of the numbers were over 360. My eyes popped when we started to see images in the mirrors. Can there still be a logical explanation to this? I think this clears up something from last episode, though. The cave list was not Jacob's. Why would he need that when he has a decent and orderly list at the lighthouse, right at his fingertips with a useful device, too. I don't think he lied to Hurley; they wanted to turn it to 108 to draw (lead?) someone else to the island to help out, but Jacob didn't need it. It was just more important for Jack to realize how special he is.
But who still thinks that Jacob could end up being bad? His actions in this episode, if anything, reminded me of a loving father. "Sometimes they can just be told in a taxi cab. Other times you have to let them stare at the ocean for a while."
Lost still delivers! --Dretzle 15:16, February 24, 2010 (UTC)