Did you see Lost on Tuesday? If you didn't and don't want to hear what happened then please don't read further.
OK, here's my question, if Claire's body was taken over by some evil force, wouldn't she have had to die first? Wasn't she alive and well the last time we saw her in the "cabin" with Jack's father?
Also, they better start explaining a bunch of the new mysteries soon including how the two different realities can co-exist (what the...) because the not knowing is driving me nuts!