Very exciting episode with starts the season final information revealing. What I like on this season is, that they finally have started to use those little hints they have set in previous seasons. The story somehow starts to have a connection and logic.
Locke got another flashback this season. wow... and it is really interesting one. When for a second I could believe that he was going with them, then this episode reveals the truth. And the way he manages to get Saywer into his trap. It was so great to see Black Rock again. And Rousseau there. They were chatting like nothing was going on next to them. The only question I got was, why did she need dynamite. But I know now, that this is answered later.
And all the others - the way they do not trusts Jack. The way things are getting out of the hands but .. it is enjoyable to watch how some other characters are trying to lead instead Jack.
For the flashbacks and the storyline over Lock - this episode is superb.