(written from a Production point of view)
In the "mirror universe," Sisko must persuade the alternate version of his dead wife to join the Terran Rebels, or he will watch her die a second time.
Sisko, Odo, and Quark are in the station commander's office debating the disposition of 27 Cardassian voles which Sisko claims are intended for fighting. Apparently Quark and Morn were discovered painting numbers on the voles' backs in Quark's storeroom, even though Quark claims that they were Morn's pets. Sisko orders that the voles be confiscated, suggesting that if Morn wants new pets, he can get some goldfish instead. Quark says "Poor Morn. This is gonna break his hearts."
Sisko then walks out into Ops, where he tells an unnamed lieutenant "Ops is yours" and walks toward the turbolift landing… just as the car arrives carrying O'Brien, who is out of uniform, which surprises Sisko, who asks if O'Brien is going somewhere. As O'Brien steps off the turbolift, he tells Sisko that he needs to converse privately, then after Odo leaves with Quark draws a phaser. However, Sisko immediately orders the Ops crew to stand down.
After ordering Sisko onto the transporter pad, O'Brien waves a multidimensional transporter over the normal transporter controls, after which O'Brien and Sisko transport to a raider and Sisko asks where they are. "I guess you could say we just stepped through the looking glass," O'Brien says in reply.
O'Brien leads Sisko into another compartment, and, in a quick moment, Sisko disarms him. At barrel's end, O'Brien confirms that they are in the mirror universe. Since the time last year Kira and Bashir crossed over, the Terrans have started a rebellion against the Klingon-Cardassian Alliance, and the rebellion at issue was led by Sisko’s counterpart… until he was killed when the ship he was on was destroyed by the Alliance.
Sisko demands to be taken back to his own universe, as he can't further influence events there. O'Brien then encourages him, explaining that, in his universe, Jennifer Sisko is very much alive, working for the Alliance on a trans-spectral sensor array that will enable the Alliance to root the rebellion out of their bases in the Badlands. In closing, O'Brien explains that if Sisko will not retrieve her from Terok Nor, the rebels will be left with "no choice but to kill her." Sisko concedes than he cannot bear the death of a second Jennifer Sisko, and agrees to attempt her rescue.
On Terok Nor, Jennifer Sisko arrives at Intendant Kira's quarters, clearly not enthusiastic about talking to her. The Intendant informs Jennifer that her husband has been killed, but she is not fazed, as they did not part on good terms.
Back on the raider, O'Brien – or rather "Smiley," as he's reminded Sisko to address him – explains that Jennifer despises her late husband, who was much better at fighting than leading. Finally the two of them transport to a rebel base, where a new mission is under discussion. It appears Bashir is ready to take charge of their force, and wants to simply smuggle explosives on the station and detonate them, no matter the risk. Just then, Sisko and Smiley enter. As Bashir looks on Sisko with a gimlet eye, Tuvok points out that they all thought Captain Sisko dead. Sisko attributes it to propaganda. He successfully wins over the group with his confidence, but then Jadzia saunters in to give Sisko a kiss of gratitude, a slap across the face for letting her think that he was dead, and a question: "are you coming or not?" Sisko hangs back so that Smiley can explain to him that Jadzia is Sisko's mistress. Jadzia seduces a reluctant Sisko, who returns her advances.
On Terok Nor, the Intendant is dismayed by the decreased productivity on the station. Garak insists he's doing all he can, but she takes him down to the processing center and orders gratuitous executions of Terran slaves as an incentive. Garak suggests that she's been in a foul humor… ever since Captain Sisko was killed. The Intendant denies it, but she is clearly frustrated and Garak knows it.
As the rebels are restless about the impending completion of the sensor array, a suspicious Jadzia is telling Sisko that she is tired of fighting the Alliance, after not seeing progress for a year. She's tired of living on the run, and says they ought to just abandon the rebellion, as their group of ex-slaves with delusions of grandeur are not capable of winning. Sisko says he's not ready to give up just yet, and they must make sure Jennifer Sisko does not complete the sensor array.
Later, with the whole group, Sisko insists (over Bashir's objections) that Jennifer's rescue, not her death, is their next objective. Bashir continues to argue, and, quietly during, O'Brien suggests to Sisko that he hit him, as the other Sisko would. He quickly goes over and hits him just as he starts talking about his wife. He berates him for doing so, though Bashir and Dax remind him it would be much easier to kill her than to convince her to leave. O'Brien reminds them that they need a scientist to help them counteract the Alliance's efforts.
On Terok Nor, Rom is on the station to inform the Intendant that Sisko is alive… and that he has information that will lead to Sisko's recapture.
Sisko and Smiley, in a fighter, soon become surrounded by decloaking Alliance ships en route to Terok Nor, captured, and taken to the station. The first thing Sisko does upon leaving the airlock is to kiss the Intendant passionately, and they briefly discuss the likelihood of his execution. Kira then moves onto O'Brien and chastises him for betraying the Alliance. After Smiley explains that he did it because he wanted to be free, Kira contemptuously orders him sent back to Ore Processing, and she leads Sisko back to her quarters. Once there, she explains to him that since she can't trust him, it will be a matter of time before she needs to "dispose of" him.
Later, Jennifer arrives, accompanied by Garak, who leaves no doubt as to his hatred of Sisko. After Garak leaves, Ben and Jennifer spar over Ben's bellicosity and womanizing, but Ben puts that to a stop by explaining that he's on the station to rescue her.
After more arguing, Ben uses the adversarial nature of their marriage as a wedge to suggest that she's working for the Alliance as a response to his leadership of the rebellion, and finally asks her to defect as an alternative to slavery. Sisko tells her to think about it, then uses a subdermal communicator to alert Smiley to his progress and disables the guards on the Intendant's quarters. Smiley creates a diversion to get himself and several slaves out of Ore Processing, while subduing a few guards in the process.
With Ben guarding the door with two Klingon disruptors, Jennifer ultimately agrees to follow him – though only after insisting that she still hates him – and the two of them meet up with Smiley and the (former) slaves in the Habitat Ring. They need to coordinate to subdue a few Cardassian soldiers, but they successfully reach the airlock where Rom's shuttle is docked, only to discover Rom's corpse hanging from the airlock door, by a dagger through the chest.
On the verge of being overpowered by the Intendant and her men and with no obvious means of leaving Terok Nor, the rebels head back to Ore Processing with Jennifer in tow. Once there, the rebels engage in a firefight with the guards, and after promising Jennifer that he will get her off the station, Sisko starts manipulating a console, explaining to Smiley that he hopes the designer of the Mirror Universe Terok Nor is the same Cardassian who designed Deep Space 9.
The Intendant and the troops with her ultimately force entry to the rebels' haven in Ore Processing, where she orders the rebels (excepting Jennifer) killed – only to have Sisko tell her that doing so would be a mistake… because he has initiated the station's auto-destruct sequence. Thinking that he's bluffing, the Intendant points out to Sisko that he doesn't know the needed command authorization code, at which point he proves her wrong. When she tries to stop the sequence, she discovers that Sisko has changed the command code, and offers to let him off the station if he will give her the new code. He demands that he and his companions be let off the station first, and the Intendant capitulates, closing with an oath to Sisko that she will hunt him down.
After the trip from Terok Nor to the rebel base, Jennifer insists on knowing who Ben really is. Commander Sisko tells her that she can ask Smiley to fill her in on the details, and then the two of them say their goodbyes when Smiley arrives to take Sisko back home.
"Poor Morn. This is gonna break his hearts."
- - Quark
"Where are we?"
"I guess you could say we just stepped through the looking glass."
- - Sisko and Smiley upon arriving in the mirror universe
"I can't let her die, not again."
"You're the only one who can save her."
- - Sisko and Smiley, regarding the mirror Jennifer Sisko
"I hope you don't run up against too many surprises."
"If I do, I guess I'll just have to… improvise."
- - Smiley and Benjamin Sisko
"Logic isn't going to win us our freedom. We have to take action!"
- - Rom (mirror), to mirror Tuvok
"At least someone here is using his brain."
- - Sisko, about Smiley
"You know, you did pretty good back there. I don't think anyone suspected you weren't Captain Sisko. At least, not once you hit Bashir."
- - Smiley
"What was your Jennifer like?"
"She was the kindest, most caring person I ever knew."
"I wouldn't get my hopes up."
- - Sisko and Smiley
"Whatever shall we do about O'Brien?"
- - Intendant Kira, condescendingly
"If you need anyone to beat him into submission for you, please don't hesitate to call me."
- - Garak (mirror), while leaving Jennifer alone with Sisko
"Do I get a vote?"
"Of course you do. It just doesn't count."
- - Sisko and Intendant Kira
"Why don't you start by telling me what happened to my husband. He's dead, isn't he?"
- - Jennifer Sisko (mirror) and Sisko
Story and script
- Robert Hewitt Wolfe pitched the story of Sisko going to the mirror universe to replace his counterpart. Wolfe commented, "From there we went back and forth about whom he should rescue, until Ira [Steven Behr] came up with the idea that it should be Jennifer, which I thought was a stroke of genius." (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 94)
- Tuvok (played by Star Trek: Voyager's Tim Russ) was included at the request of Rick Berman. Sakonna ("The Maquis, Part I") was the original character. (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 94)
- Jonathan West was the director of photography for the episode. West commented, "We used more cross-lighting and stronger back-lighting. I changed the white fluorescents in Sisko's office to red by covering them in a red gel. And in the ore processing facility we used a mix of blue light and darkness, and more smoke than usual." The smoke was added at the request of Director Winrich Kolbe, who commented, "I like to use smoke, because it gives an interesting visual. Plus, I think it takes the edges off sets that have been shot ten thousand times. The cave set, for instance, has been shot over and over again in both TNG and DS9." (Star Trek: Deep Space Nine Companion (p. 230))
- Nana Visitor hated the Intendant's rubber, figure-hugging outfit, later claiming, "It didn't breathe at all." Between takes, she had to stand in front of a large fan to prevent her from sweating, as sweat tended to discolor the outfit. (Star Trek: Deep Space Nine Companion (p. 230))
- Ira Steven Behr commented, "We certainly had enough stuff that could have kept that show going another hour. I thought the Sisko/Jennifer relationship was interesting. It was a nice way to bring Jennifer back, and I think we'll meet her again. Jake is going to have to see her at some point. The action stuff was pretty cool. I thought that the look of the show was good. My only complaint is that we had to cram so much into too little time". (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages, p. 94)
- Avery Brooks was especially happy when he read the teleplay for this episode, because in it, Sisko has sex for the first time since the show began. And not once, but twice; first with Jadzia Dax and then with Kira Nerys. (Star Trek: Deep Space Nine Companion (p. ?))
- The Deseret News thought Tim Russ' appearance as Tuvok a ratings ploy. 
- The name "Through the Looking Glass" was the last line Major Kira had in the season 2 Mirror universe episode ""Crossover".
- This episode was filmed after "Improbable Cause", but before "The Die is Cast" because the decision to make "Improbable Cause" a two-parter came so late in the schedule that "Through the Looking Glass" was already in pre-production.
- This episode picks up in the mirror universe where "Crossover" left off. "Crossover" had itself been something of a sequel to the TOS episode "Mirror, Mirror".
- This episode contains the only reference to the Romulans in the mirror universe.
- Alliance ships are seen de-cloaking in this episode. This is in direct contradiction with the episode "The Emperor's New Cloak", where a major aspect of the plot deals with a delivery of a cloaking device to the Alliance, who don't possess the technology. Non-canon novels attempt to explain this as the difference between Alliance cloaks and Romulan cloaks.
- This episode takes its name from the 1871 Lewis Carroll book Through the Looking-Glass. The sequel to Alice's Adventures in Wonderland, the book features Alice's further adventures in a fantasy world beyond a mirror. It is also the phrase Smiley uses to "welcome" Sisko in the mirror universe early in the episode. Kira also uses the same phrase at the end of "Crossover", when asked where she and Bashir have been.
- In the opening scene where Sisko has ruled that the Cardassian voles should be confiscated, Quark says it will break Morn's hearts, plural, implying that Morn's species has more than one heart.
- Cirroc Lofton (Jake Sisko) does not appear in this episode.
- Kira Nerys, Miles O'Brien, Jadzia Dax and Julian Bashir do not appear in this episode, only their mirror counterparts. The only regular characters who appear are Sisko, Odo and Quark.
- The raider's corridor, transporter room, and the turbolift, are redresses of the USS Defiant sets, using computer graphics from Star Trek VI: The Undiscovered Country. To make it look different, the lighting department used a harsh red light to contrast with the bright white lights of "our" universe. The raider's bridge was a redress of the Runabout cockpit, which had been re-dressed in the same style, several months earlier, as the Maquis raider Val Jean in VOY: "Caretaker".
- Though referred to as a Terran raider, the model of the ship itself resembles a Bajoran interceptor.
- This is the second of two consecutive episodes to feature no scenes with the real Kira or O'Brien but only alternate versions of them: the representations of them in Bashir's mind in "Distant Voices" and their mirror universe counterparts in this episode.
Video and DVD releases
- UK VHS release (two-episode tapes, CIC Video): Volume 3.10, 7 August 1995
- As part of the DS9 Season 3 DVD collection
- As part of the Star Trek: Fan Collective - Alternate Realities collection
Links and references
- Rene Auberjonois as Odo
- Siddig El Fadil as Doctor Bashir
- Terry Farrell as Lieutenant Dax
- Cirroc Lofton as Jake Sisko
- Colm Meaney as Chief O'Brien
- Armin Shimerman as Quark
- Nana Visitor as Major Kira
Special Guest Star
- Darcie Armstrong as Terran slave
- Patrick Barnitt as Bajoran officer (mirror)
- Scott Barry as Bajoran officer
- Pam Blackwell as Terran slave
- Robert Coffee as Bajoran officer (mirror)
- George Colucci as Terran slave
- Chris Doyle as Cardassian officer
- Siddig El Fadil as Julian Bashir (mirror)
- Terry Farrell as Jadzia Dax (mirror)
- Ken Lesco as Bajoran officer
- Dan Magee as Terran marauder
- Joyce McCoy as Terran slave
- Colm Meaney as Smiley (mirror)
- Tom Morga as Klingon officer
- Joe Murphy
- Stuart Nixon as
- Lisa Pettett as Terran slave
- Bob Shuttleworth as Terran slave
- Steph Silvestri as Terran marauder
- Michael Tierney as Cardassian officer
- Chester E. Tripp III
- Nana Visitor as Kira Nerys (mirror)
- Unknown performers as
- Eight Terran slaves
- Bajoran female officer
- Bajoran female officer
- Bajoran female officer
- Bajoran male officer
- Bajoran male officer
- Cardassian officer
- Cardassian officer
- Cardassian officer
- Eight Terran marauders
- Klingon officer
- Klingon officer
- Klingon officer
- Terran male servant
- Terran female servant
- Vulcan servant 1
- Vulcan servant 2
- Faye Barge as stand-in for Felecia M. Bell
- Ivor Bartels
- John Lendale Bennett as stand-in for Avery Brooks
- Mark Lentry
- David B. Levinson as stand-in for Max Grodénchik
- Randy Pflug as stand-in for Colm Meaney
2366; 2370; access code; airlock; Badlands; bedroom; bluff; bribery; Cardassians; cloaking device; confiscation; Constable; current events; Ferengi; flattery; freedom; Galor-class (unnamed); goldfish; heart; husband; Intendant; kiss; Klingons; Klingon-Cardassian Alliance; leader; logic; manual override; massage; mine; mistress; Morn; ODN processor; ore processing; overseer; paint; pet; pig; pilot; pirate; productivity; professor; propaganda; Quark (mirror); quarters; quota; rebel; revolution; Romulans; Sector Command; slavery; storeroom; subspace; subdermal communicator; Terok Nor (mirror); Terran base; Terran fighter (aka "raider"; unnamed); Terran Rebellion; surrender; theta; tinkerer; torture; transpectral sensor array; vole; vole fighting; Vor'cha-class (unnamed); vote; witch; worker (aka workforce)
- "Through the Looking Glass" at Memory Beta, the wiki for licensed Star Trek works
- "Through the Looking Glass" at Wikipedia
- "Through the Looking Glass" at StarTrek.com, the official Star Trek website
|Mirror universe-related episodes|
|ENT: "In a Mirror, Darkly" • "In a Mirror, Darkly, Part II"|
|DIS: "Into the Forest I Go" • "Despite Yourself" • "The Wolf Inside" • "Vaulting Ambition" • "What's Past Is Prologue" • "Terra Firma, Part 1" • "Terra Firma, Part 2"|
|TOS: "Mirror, Mirror" • "The Tholian Web"|
|DS9: "Crossover" • "Through the Looking Glass" • "Shattered Mirror" • "Resurrection" • "The Emperor's New Cloak"|
|Star Trek: Deep Space Nine