I agree Baldkin. this is exactly what my wife and I discussed last night. They surely could have put that episode sooner into this season's schedule, couldn't they have? Instead, they have been rising and rising and rising with the plot up to the climax (we hope) of the finale and then they bring out this episode that killed all that momentum. And, yeah, the whole "light" thing in the water? BOOOOOO writers! (unless you explain it in the final 2 episodes). All I can think of is that the light was a "prison" or something for the evil (smokey) of the world and "mom" (allison janney) was the warden and told Jacob not to enter so he wouldn't let the evil out. But when he put his brother in, the evil (smokey) escaped and shape shifted into his brother. With Jacob realizing that his brother was already dead, he knew that the MiB that he sees and converses with later on is not his brother and so he vows to make sure he can't leave the island. Now, WHY they can't leave the island???? I wish they'd explain that one. I actually wish there was another episode/hour following last night's to see how Jacob came to realize all this and how/when/why he made the "list" of candidates, built the lighthouse/mirror thing, the statue with 4 toes, etc. (if he even did any of that stuff.) Maybe they'll explain all that in the novels that they are planning.