Live Together, Die Alone (1)

After discovering something odd just offshore, Jack and Sayid come up with a plan to confront "The Others" and hopefully get Walt back. At the same time there will be an answer to the question of where Michael has been and resolution of him and Walt. Meanwhile, Eko and Locke come to blows as Locke makes a potentially cataclysmic decision regarding the "button" and the hatch. Lastly, Desmond returns and he sheds some more light on his experience on the island in the three years prior to when Locke came down into that hatch.