I really didn't like this episode just because it was so predictable. First scene with Dave on island, ok ok he's some imaginary friend. Cut to the flashback with Dave in the hospital. Yeah, he's clearly imaginary, no one is interacting with him, I've scene this in Sixth Sense. Forty minutes later, GASP he doesn't exist! And gasp! Libby appeared at the end! Wasn't surprised by that either. There was a slight chance they'd just show her right away, but knowing this show, I knew they'd wait to show her at the end.

I don't mind character development, but basically we learned a lot of things we already know and probably got a lot of red herrings too. I was much more interested in Locke and his development.