it be libby talk to desmond in the flashback and and if anyone be confuse about her past ( like how do she end up in the same hospital hurley be in ) then you should know that despited libby die in season 2 and the character will be explore more in season 3 and we will get answer to question surround her . btw and great episode . it have a really great cliffhanger and some interesting question . like what happen to eko and lock and what about the four toe statue . i can not wait till season 3 and lose just rule . i hope all the unanswered question will be answer . i love how they explain why the plane actually crash . desmond do it when he do not manage to type in the number in time . 4 8 15 16 23 42 .