So this is building up on what a lot of people have discussed.
I believe that the island (maybe the monster) can possess things when they are dead. This is why burying the bodies is so important. There was no sickness, Danielles crew was possessed after they died and thats why they tried to kill her. It possessed Christian and now Locke. Locke was told that he had to die to get everyone back. He heard this from Christian, and then told Richard to tell his past self the same thing. Christian probably told him he had to die and return because if he did so he knew Lock could be possessed. Christian and Locke are on the same side, as is probably Richard. Whatever force is behind this it seems to be getting its way, and locke is definitely different, with different motivations then prior seasons.
I believe that the island (maybe the monster) can possess things when they are dead. This is why burying the bodies is so important. There was no sickness, Danielles crew was possessed after they died and thats why they tried to kill her. It possessed Christian and now Locke. Locke was told that he had to die to get everyone back. He heard this from Christian, and then told Richard to tell his past self the same thing. Christian probably told him he had to die and return because if he did so he knew Lock could be possessed. Christian and Locke are on the same side, as is probably Richard. Whatever force is behind this it seems to be getting its way, and locke is definitely different, with different motivations then prior seasons.
