Deep Space Nine 3x19 "Through the Looking Glass"

rating: ****

the story: Sisko is brought to the Mirror Universe to confront the most unlikely foe: his dead wife's doppelganger.

what it's all about: What's even more unlikely than Deep Space Nine producing one classic sequel to the original series classic "Mirror, Mirror" (last season's "Crossover")?  Producing a second.  (And, also, a third: next season's "Shattered Mirror," completing arguably the best trilogy of the whole franchise.)

You really only need to look at the story summary, a truly genius move that few other shows would even consider as a possibility.  What's most brilliant about it is that the actress whose minor appearance as the late Jennifer Sisko in "Emissary," the first episode of the series, returns, for a far more substantial role.  It's a gamble that absolutely pays off.  Even if you don't think the actress nails it, Avery Brooks does.  It's one of the key performances in a season full of them, a season that redefined Sisko as the true lynchpin of the series, after a few seasons in which that was never a certainty.  It happened with Picard, too, but Sisko's accomplishment is the greater for having so much demanded of him in one season and every time proving to be up to the challenge, as if all of Picard's best moments were in the third season.  (I mean, there's still "Pale Moonlight" and "Far Beyond the Stars" in the sixth season, but it's still incredibly hard to stack anything up against Sisko's appearances this season.)

"Looking Glass" at last tackles the elephant in the room, which two previous seasons had danced so badly around, Sisko's devastating loss, the central element of the very first episode, for him.  Seeing it finally revisited, and brilliantly, was a moment that really had to happen, but the way it happened is the genius of the episode, in another trip to the Mirror Universe, the signature alternate reality of the franchise (revisited several other times in the series besides, plus the two-part Enterprise entry "In a Mirror, Darkly").

The third season scored so well with Sisko because it constantly put him in discombobulating situations, and each time he proved worthy to the task.  The Mirror Sisko we met in "Crossover" was about as far from the Sisko we knew then, and later, as you could get, so to see that character reverse-engineered, not even to talk about the Jennifer element, is to see exactly how Sisko goes about making decisions.  That's probably the best way to view the episode if you don't particularly care for the greater implications, which is what you should be able to say about classics, whether they can work on multiple levels, and how much they challenge the viewer.  Anyone who thinks this might just be a Mirror Universe rehash will have to admit that it adds significant new wrinkles to the formula.

But the Jennifer element is definitely good enough to warrant classic status all on its own.  Everyone in the episode clearly enjoys the possibilities given them.  This one is really hard not to love.  If none of what I've already said sells it for you, just think of this: "Looking Glass" also sneaks in the craftiest interseries character appearance ever, with Voyager's Tim Russ appearing as Mirror Tuvok, with no one really drawing attention to it.

criteria analysis:

• franchise - Another fruitful trip to the Mirror Universe.
• series - Another in a fruitful series of Deep Space Nine trips there.
• character - Sisko comes face-to-face with the specter of his dead wife.
• essential - Too darn good to ignore.

notable guest-stars:
Felecia M. Bell (Mirror Jennifer Sisko)
Tim Russ (Mirror Tuvok)
Andrew Robinson (Garak)
Max Grodenchik (Rom)
Dennis Madalone