the story: The Defiant is destroyed by the Dominion's new allies, the Breen.
what it's all about: Well, this certainly never happened in Star Trek before. Yeah, Voyager would later do it with the Delta Flyer, too, but Deep Space Nine got there first. It destroyed one the franchise's signature ships, during the course of a series.
So that makes "The Changing Face of Evil" one of those essential moments in the closing arc of the Dominion War. I guess, at this point everything seems like an essential moment in the arc, the serialization taking shape at last to feature big moments each episode and not mere running material for the sake of it. Each one has its own specific purpose. This one makes it clear that the war is definitely still being fought.
Other big things are the news that Earth has been attacked, and that Winn has made the big decision to commit herself to reading a Pah Wraith book, thereby committing herself to Dukat's plan. And that title? Yeah, she's found out that the Bajoran farmer who's been helping her was Dukat all along. Oh, and news has finally gotten out that Damar has defected from the Dominion.
This is an installment that deepens existing plot threads more than anything, raising the stakes just a little more.
franchise- I'm not sure the loss of the Defiant, or the replacement that shows up in the final episode, is something that's communicated properly for general fans to really care.
- series - The war heats up!
- character - Winn's role in these final episodes is perhaps the best she is all series.
- essential - The loss of the Defiant is a powerful symbolic gesture.
Louise Fletcher (Winn)
Marc Alaimo (Dukat)
Casey Biggs (Damar)
Jeffrey Combs (Weyoun)
Salome Jens (Female Founder)
J.G. Hertzler (Martok)
Barry Jenner (Admiral Ross)
Aron Eisenberg (Nog)
Penny Johnson (Kasidy)