SPOILER ALERT!!!!!!!!!!!!!!IF YOU READ BEYOND THIS POINT, YOU WILL KNOW WHAT HAPPENED ON LOST LAST NIGHT!!!! YOU HAVE BEEN WARNED!!!!
At the start, Juliette (blonde "other" trying to feed Jack and the one who zaps Sawyer with a stun dart.) is hosting a book club meeting at her home...none of the people look familiar (I actually thought the channel got changed and I was watching the wrong show). Anyway, mid book club meeting, there is and earthquake type situation. Everyone runs outside, neighbors do the same, one of the neighbors is the head "Other"...aka "Henry". They look up in the sky, see a low flying plane, watch it tear into two and the tail end lands on the other side of the island. Henry says "Did you see where the tail landed?" Then he starts barking orders "Ethan, your one of them, I want a list in 3 days (or something to that extent)" and he continues a few more orders that makes it appear like the plane crash was as new to them as it was anyone else. Camera zooms out and you see a small housing development where all the others reside in the middle of the huge, gigantic jungle of an island.
Flash backs were all of Jack and Sarah as they proceed with the divorce. She is seeing someone else and he wants to know his name. He starts to think it is his Dad but learns later that it is not his Dad.