Due to my computer problems this is late, haphazard, and uninformed by any online discussion. But it's still my first thoughts on...
While I didn't get to jot down as many memorable lines as usual, an early one made a lasting impression: "How do you lose a body?"
Jack's mother said this in the Alternate Universe as they discussed Oceanic's misplacement of Christian Shephard, but I thought immediately of Locke. He suffered unimaginable indignity in death — he was despondent to the point of suicide, only to have Benjamin Linus "save" and then murder him, after which his body was brought back to the Island but he was not; instead, Smokey manifested in Locke's likeness. (Now that's identity theft.)
The episode's flashsideways focused on Jack as he connected to the son we never knew he had, partly because until now he didn't necessarily exist. Even his name surprised me. David? I figured it would be Geronimo. And am I the only one who thought he looked eerily like the love child of Matthew Fox and The Jonas Brothers? For her part, Jack's mother Margo — seen briefly at Christian's Original Universe memorial in Season 4 and in a Season 1 flashback — looked like a cross between Morticia Addams and an aging Lynda Carter; as it turns out, she's played by another raven-haired siren of bygone TV, Hill Street Blues' Veronica Hamel.
Sure we've seen it before, but the climactic piano recital was touching — credit Fox for showing his range once again, from angst to pride to fierce anger across two realities — and it reminded us that, for all the potential Island enlightenment the AU versions of our castaways may have "lost" by never having become castaways, their lives as untouched by the Island's influence seem whole.
David's existence and that appendectomy scar of Jack's are further evidence that when the Island sank in AU 1977 the butterfly effect of the event extended not just to those in the immediate vicinity, like the presumably evacuated Ben or Ethan Goodspeed, but future "candidates" or other persons of interest to Jacob, who now have led lives as different in some ways as they are similar in others to their OU versions. Hurley feels lucky and happy; John is with Helen; what AU Kate did is apparently different from what OU Kate did, although I think that's still technically extracurricular info not yet covered in the show. Some of this may be due to lack of human interference from the likes of Charles Widmore, but much of it likely stems from either the absence of Jacob or at least a different approach necessitated by the H-bomb explosion. Yet destiny or something like it still brought many of the OU castaways together on Oceanic 815 in AU September 2004, and located Ben, Ethan, and Temple leader Dogen in the same Los Angeles environs as the Oceanic travelers. (Dogen's appearance bolsters my hope that we'll see Alex Rousseau talking back to Ben in one of his history classes. "Shove it, Mr. Linus! You're not my father!")
The subplot of what happened to Christian's missing coffin and, more importantly, what may or may not be inside is likely going somewhere big, but in this episode it served mostly to do two things: (1) Inject the name Claire Littleton into Jack's AU existence, by extension linking those scenes to Claire's present-day OU Island adventures as well as Jack's, and (B) cause me to all but shout at the television, "Let's see if Dad's will is filed neatly on the mantlepiece bookshelf behind his desk — right after we dig through all these boxes!"
Despite the fact that we last saw her sitting serenely in Jacob's cabin with Christian, Claire's evidently been living like half-mad Frenchwoman Danielle for some time. Her piercing blue eyes still shine out through her paranoia, grime, and crazy jungle pseudo-mullet — bird's nest in the front, electroshock therapy in the back — but whether it's due to Smokey's influence, some kind of undead state, or just the trauma of three years without any human companionship, Claire isn't quite right.
The crib and its contents were sure a strange sight, partly because Claire does understand that Aaron's not with her and partly because that makeshift totemic baby came complete with an animal skull whose snout made it resemble the Island's statue of Taweret. Speculation on not just where Claire was but what she was has been simmering for a couple of seasons now; one thing she doesn't seem to be is beyond the physical realm, although in that place and with these storytellers we can't be sure. The house where she resided when the castaways succeeded the Others as occupiers of the old Dharma Initiative lodgings was blown up good by Widmore's freighter mercenaries, but she seemed unharmed at the time. Miles saw her walk off into the jungle with Christian in the middle of the night, however, leaving Aaron behind near Miles and Sawyer; her only appearance since then in the Original Universe was in the cabin, placid and unconcerned about her son. Lots of folks have wondered if she didn't actually die when her house was attacked, but if she did she got up and kept moving right away without benefit of the Temple's healing pool. Her change of heart or mind over Aaron's whereabouts is puzzling, as is her exact interaction with Christian or whomever he may be and the figure she knows not to be Locke and simply calls "my friend".
Dogen told Jack that his sister had been "claimed" as Sayid was, and if that's true she could count as another body lost. "If there's one thing that'll kill you 'round here, it's an infection," she told Jin in a comment as pregnant with meaning as she was with Aaron when the series began. Of course, Aaron is lost from Claire's perspective, believed to have been taken by the Others when in fact Kate has traveled back to the Island to bring Claire back to her son in LA. Jacob has also lost his body, or at least the only body of his we've seen, but that hasn't kept him from appearing to Hurley, this time to direct Hurley and Jack to that lighthouse with its magic multifaceted mirror. You could even stretch the association to include Alternate Universe Jack's feeling of losing touch with his own body, first staring into the mirror in the airplane lavatory in the season premiere and now having to ask his mother about his appendectomy scar. Will he ever learn that there's another one of him out there, through the looking-glass, still chasing his own white rabbit?