As for what makes “Ab Aeterno” a Lost story, I have to point to a narrative structure that has the protagonist in shackles and in the dark for a good chunk of the episode. That’s Lost in a nutshell, yes? There’s so much we want to see, and so much we want to know, yet again and again, the writers lock us into one place, and leave us there in ignorance until our spirits are broken. And then just when we’re about to give up they take us someplace new and unexpected, and we’re so grateful that we’ll believe anything they tell us. It’s quite canny, how often Lost becomes a metaphor for itself.
