A few thoughts on Charlie and Ethan, and my new loony theory.
Poor Charlie! Although that was some pretty good shooting... I bet Charlie knows how to use a gun too.
As for Ethan, I at least have been assuming that his strength may be supernatural, based on kicking Jack's butt one and a half times, and lifting up Charlie. Charlie is a recovering addict, marooned on an island... he's by far the lightest guy there, and probably even lighter than he should be, given the lack of food and the withdrawl. Jack is by no means a fighter... while it certainly looks punishing when Jack beats him the second time, look how fast Ethan recovers. I don't think Jack was really hitting that hard. Furthermore, I'd bet Ethan was just toying with him, or knew about the others in the woods. Which begs the question, why didn't he disable them first?
Finally, my new wacky theory is that the sickness turns normals into Others. Ethan looked sort of European to me... I'm wondering if the others on Danielle's expedition went mad and became the Others. Furthermore, with regards to the large ensemble cast, I wonder if a large part of them are going to become Others as well, just by getting sick.
