It was a good episiode but there is still a lot of unanswered questions. I believe that the MIB is actually immaterial. He is just the remaining soul of Jacob's brother inhabiting his original body. But his REAL body is dead in a cave. I remember when he first met Richard he said the devil stole my body referring to Jacob who pushed him into the light. I also think MIB inherited much of the power of the SOURCE and it is in effect the heart of the island. He can never leave or die or else the island would cease to exist. He is not as evil as has been portrayed. He is stuck forever. Remember in last night's episode the crazy mama tells Jacob going into the light is worse than death, i think she meant the punishment is being on the island for eternity. Also she says thank you after MIB kills her because she is probably tired of guarding that well. She could have been guarding that thing for hundreds of years for all we know. Jacob also didn't seem outraged at Ben killing him, he was upset Ben did it but he didn't put up a larger fight-he was probably tired of guarding MIB(the light) and was ready to pass it off to a new candidate. He intentionally brought Jack Sawyer and the rest of the candidates to the island, he didn't plan on being their forever, and the crazy mother killed the other mother because she didn't want to be their forever and what more ideal situation to raise two boys to be the protectors. But I'm still not sure WHERE exactly MIB wants to go or WHY he helps Ben when he is summoned or HOW the crazy mother killed all those people and buried that huge hole so fast or WHAT the exact significance of the wine the crazy mother and Jacob drinks is. Richard alo drank it so maybe it keeps you at that age forever, but it does not give you complete immunity. The island must have been done with Jacob based on the fact it let him die. There is still obvioulsy some higher power than any single person, maybe the power s from the light source?