It’s loaded with exposition, voice-over narration, and flashbacks — three things screenwriting experts say don’t do. And yet it works. It’s not the show’s greatest episode, but it succeeds in getting us interested in this world and situation (well, enough of us to make a movie possible several years later).
On the other hand, when the Green Lantern movie opened with voice-over exposition, I knew we were in trouble.
The lesson: Break rules skillfully, but do not break rules awkwardly. (And people say adverbs never amount to anything.)