What sets "Promise" apart from your standard CW drama is its unique structure. The episode tells the story of the wedding day three separate times, each from the perspective of the main players:
We see the raw desperation of a hero who realizes too late what he’s losing. Clark finally resolves to tell Lana his secret to save her from a loveless marriage, only to have his hopes crushed by a literal closed door. [S5E3] Promise
A deadly vow to Lex that Lana will be at the altar, and a threat to Lana that he will kill the man she loves. What sets "Promise" apart from your standard CW
The episode ends on a haunting visual: Clark standing alone in the rain, watching the limousine carry Lana away. It effectively signaled the end of the "Smallville" of old. The era of pining in the hayloft was over, replaced by a much darker, more mature conflict between the future Man of Steel and the greatest villain of his life. A deadly vow to Lex that Lana will
The true MVP of this episode isn't the groom or the hero; it’s . Just as Lana prepares to leave Lex for Clark, Lionel intervenes with a chilling threat. He reveals he knows Clark’s secret and his one weakness, promising to kill Clark unless Lana goes through with the wedding.
According to reviewers on IMDb , the cinematography and the heartbreaking score by Mark Snow elevated this from a "boring soap opera" to one of the most memorable climaxes in the series.