It's time for the annual Mirror Universe episode! This time, Quark gets a visit from Mirror Ezri, who tells him that Grand Nagus Zek is in the alternate universe, and he has been kidnapped by the Alliance. Quark has to provide Regent Worf with a cloaking device, and in return he'll free the Nagus. However, Quark doesn't trust the Regent to keep his word, so he and Rom travel with Ezri to the Mirror Universe to make sure the Nagus gets back home.
- Asshole Victim: Even Andrew Robinson was overjoyed when Mirror!Garak was killed.
- Audience Surrogate: Ira Stephen Behr had grown quite bemused with all the fans who seemed to take the Mirror Universe with deadly seriousness and demanded everything in the inherently silly idea make perfect logical sense. So he gives all their struggles to understand how it works to Rom, who ultimately just gives up trying to make sense of it.
- Badass Gay: The mirror universe's Ezri is a lesbian, and a Knife Nut that you don't want to trifle with.
- Bizarro Universe: Discussed Trope, though when a Mirror Universe Vic appears, everyone just gives up.
- Casual Kink: When a black-clad Ezri puts a knife to his throat, Quark assumes she's into fantasy roleplay. Quark does not appear adverse to the idea.
- Contrived Coincidence: The most contrived of them all. Somehow, there's a flesh and blood Mirror Universe counterpart of Vic Fontaine, leaving everyone rather confused.
- Cruel and Unusual Death: Mirror!Garak's poison causes this.
- Curb-Stomp Battle: When Mirror Worf's flagship shuts down due to Rom's sabotage, the Defiant shoots the crap out of it.
- Depraved Bisexual: Intendant Kira has already proven to be this in the previous Mirror Universe episodes, but here she's depraved to the point of stupidity. Mirror Ezri has feelings for Kira, and she's using that to make Ezri do what she wants, but she also makes out with Regent Worf right in front of Ezri's eyes. Nana Visitor was actually quite displeased by this, having seen the Intendant's flirting with our Kira to be a purely narcissistic thing that had nothing to do with sexuality.
- Didn't Think This Through: Exploring business opportunities in the Mirror Universe is definitely not one of Zek's brightest ideas.
- Evil Cannot Comprehend Good: For a bit of a twist on "good" and "evil", but Mirror!Ezri can't understand why Quark and Rom would risk their lives for Zek without expecting anything in return.
- Evil Costume Switch: Mirror Ezri wears punk/goth style clothes with black leather and all. This gets subverted though, as she's revealed to be not so evil after all (though she's still much more amoral than the regular universe Ezri).
- Girl-on-Girl Is Hot: Zek decides the Mirror Universe isn't so bad after seeing Mirror!Leeta promising to 'debrief' Mirror!Ezri.
- Hoist by His Own Petard: Mirror Garak is killed by his own poison.
- Incompatible Orientation: Mirror!Brunt clearly has a crush on Mirror!Ezri, but he's not at all her type.
- Invisibility Flicker: The cloaked cloaking device appears a couple times.
- It Seemed Like a Good Idea at the Time: Why Zek tried to go into business with the Mirror Universe.
- Lampshade Hanging: Rom spends the entire episode pointing out all of the weird little things about the Mirror Universe, from Smiley being just as nice as the main universe's O'Brien (thus making no sense if everything in the Mirror Universe is opposite to the main universe, so Smiley should be mean) to Mirror!Brunt being a nice guy offering tube grubs (...so what if Mirror tube grubs are poisonous, because the main universe's tube grubs are safe to eat?).
- Killed Offscreen: Mirror O'Brien remarks to Quark and Rom that Mirror Jadzia was killed in a skirmish sometime after the last Mirror Universe episode.
- Lampshade Hanging: The absurd qualities of the Mirror Universe trope are lampshaded, as Rom gets very confused about which things are reversed in the Mirror Universe and which aren't.
- Mistreatment-Induced Betrayal: Mirror!Kira killing Mirror!Brunt is what makes Mirror!Ezri turn against the Alliance.
- Never My Fault: Zek got to the Mirror Universe by stealing the specs for the multidimensional transporter from Rom, so of course it's all Rom's fault!
- Nice Guy: Mirror!Brunt may be jaded and cynical, but he's a lot more pleasant than the real Brunt.
- Properly Paranoid: Smiley worries that with the Invisibility Cloak, Worf could have the Defiant in his sights without them knowing. He's right.
- Psycho Lesbian: Subverted. Mirror Ezri is gay, and when we meet her she's also a ruthless mercenary working for the Regent, even though Trill is one of the planets conquered by the Alliance. But later on we find out she's not without a conscience after all, and by the end of the episode she ends up joining the Rebellion.
- Screw This, I'm Outta Here!: Quark and Rom's decision to go to the Mirror Universe is exacerbated when Martok shows up, having discovered their theft of the cloaking device."FERENGI! I'll have you hanging by your ears!"
- Series Continuity Error: This episode is all about stealing a cloak for the Mirror Universe, which doesn't have them. Except in the first DS9 Mirror Universe episode Crossover, one of the first things to happen in the MU was Klingon ships decloaking to capture the runabout.
- Stock Footage: From "Shattered Mirror"—specifically, the scene where the Mirror Defiant shoots up Mirror!Worf's flagship, but without Worf shooting back.
- Tantrum Throwing: When Mirror Worf is forced to surrender, he rips his command chair from the deck and throws it across the bridge.
- The Tape Knew You Would Say That: Zek's message to Quark.Zek: Hello, Quark. It's me, your Grand Nagus. You'll never guess where I am.
Zek: If you said "Risa," guess again! I'm in the alternate universe.
- Threat Backfire: When Rom snaps at Mirror Garak for giving him the wrong tool.Garak: I'd advise you to watch your tone of voice, Ferengi!
Rom: Or what? You won't let me install the cloaking device?
- The Worf Effect: No matter what universe it is, our favorite Klingon is destined to fall victim to this.
- You Have Outlived Your Usefulness: Once the Invisibility Cloak is installed, Mirror Worf decides to have the Ferengi executed. (Quark even predicts that this might happen.)
- Your Cheating Heart: Zek getting oo-mox from Mirror!Kira? What would Ishka have to say about that?