Not many episodes can cut to the heart of Ben Linus like the Shape of Things to Come. This episode was dark and real. Well real besides the black smoke monster but we'll get to that.
On Lost, if we're lucky, a character's death is long and drawn out in a cinematic way. We are given closure and plenty of time to think about it. (Charlie, Boone, and even Shannon) But the rest of the time, the characters are ripped from the show realistically leaving us stunned and wanting answers. In the episode of season 4 where shit got real, we got just that.
First of all, time travel was still new and Ben's flashback was actually a flash forward but back to the past, confusing eh? That aside, the real meat of the show came with Keemy's siege of the barracks and Sawyer's uncanny ability to dodge bullets. It built to the stand off with Keemy and Ben which resulted in the death of Alex, Ben's adopted daughter. It was such a blow to the audience to have someone actually carry out a threat and kill a major character that we all watched in horror, including Ben. But that was the best part, to see Ben finally lose, to him him out of his element, to see him see his plans turn against him. For the man who always has a plan and always has something to say, was speechless.
Then to top it off, we were told that Ben can summon the black smoke monster and the attack on the mercs was absolutely satisfying. This episode was full of suspense, build up, action, and regret. And it truly was a hint at the shape of things to come.