Star Trek: Deep Space Nine Ending Explained: Greatness Demands Sacrifice

Though the "Star Trek" franchise occasionally veers into the existential here and there, no series has been as complex or as willing to stare into the void as "Star Trek: Deep Space Nine." The series has been thought of as the weird step-child of the franchise since its airing, as there's not much in the way of exploring the stars in "Deep Space Nine," instead forcing its characters to go through a variety of challenges all while living aboard the space station Deep Space Nine. Many of its characters aren't members of Starfleet or even the Federation, as Deep Space Nine sat near a newly opened wormhole and was next to the recently-freed planet Bajor after many years of Cardassian occupation. Over seven seasons, "Deep Space Nine" followed Benjamin Sisko (Avery Brooks), Commander and then Captain of Deep Space Nine, who was not only the military leader of a vital outpost, but also the Emissary of the Prophets of Bajor, the chosen one of an entire planet of people ... at least according to the aliens living in the wormhole/Celestial Temple, worshipped by the Bajorans as gods. 

"Star Trek: Deep Space Nine" used its science fiction storytelling to examine one thing other "Star Trek" shows often avoided like the plague: war. The Dominion War lasted through the show's back half, only coming to an end in the final two-hour finale, "What You Leave Behind." The finale also wrapped up several other loose ends, including curing the virus that the underhanded Section 31 unleashed on the Changelings, returning Sisko to the Prophets, and saying goodbye to all of the beloved weirdos that made tuning into "Deep Space Nine" so much fun. 

The war with the Dominion began when Starfleet first started exploring the Gamma Quadrant, accessible through the wormhole next to Deep Space Nine and Bajor. The Dominion had conquered the Gamma Quadrant, led by the Founders (known to the Alpha Quadrant as Changelings because of their ability to shapeshift). The Changeling Odo (René Auberjonois) was sent out into space and found by a Bajoran scientist and raised apart from the Founders; he eventually became Chief of Security on Deep Space Nine. The Dominion seemed to be winning the war with strategic alliances with Cardassia and later the Breen, along with their genetically-engineered workers and warriors, the Vorta and the Jem'Hadar, but then the Founders began getting deathly ill, rotting away. Deep Space Nine's Chief Medical Officer Dr. Julian Bashir (Alexander Siddig) and Chief of Operations Miles O'Brien (Colm Meaney) discover that the disease was created by Section 31 in order to get rid of the Founders, using Odo as their patient zero. Thankfully, Dr. Bashir is able to develop a cure, and they are able to use it as a bargaining chip with the Founders in an attempt to sue for peace. 

In addition to their health difficulties, the Founders also face a new threat from a Cardassian rebellion led by Legate Damar (Casey Biggs) and trained by Deep Space Nine's Bajoran first officer and former freedom fighter/terrorist, Major Kira Nerys (Nana Visitor). During a critical battle, the Cardassians fully turn on the Founders, and when it starts to look like the Dominion might fall, Odo visits with their leader and cures her, offering to give the cure to the rest of their people. In order to save the rest of the Founders, the Dominion finally stands down. 

Though the Breen are a truly terrifying force, the Dominion simply cannot succeed with the Founders dying and Cardassia rebelling. They sign a peace agreement and go back to the Gamma Quadrant, leaving a tremendous amount of destruction in their wake. Cardassia have to completely rebuild, and the Federation and their allies have suffered heavy casualties. Not only that, but Odo must go back to his home planet and join the Great Link, helping them heal using Bashir's cure and teaching them how to be better than what the Founders taught. Saying goodbye to Odo is a real bummer, as he and Major Kira had spent the previous season developing a romantic relationship that they had only just barely gotten to enjoy. However, he will be able to make massive positive changes to his entire species, making it a necessary and noble sacrifice. 

As "Deep Space Nine" wraps up, Odo is in charge of the Changelings and Rom (Max Grodénchik), the sweetest Ferengi and brother of bar owner Quark, is in charge of the entirety of Ferengi society. The Klingons and the Federation are on good terms after the Khitomer accords were almost destroyed during the war, and things seem to be headed back to a semblance of peace. Heck, the Romulans even ended up working on the same side as the Federation after some morally ambiguous intelligence work by Sisko, something that would have been completely impossible on any other "Star Trek" series. Unfortunately, there's one big, weird loose end that the show had to tie up: former Cardassian leader Gul Dukat (Marc Alaimo) trying to start a Bajoran apocalypse. 

Though the Dominion were always a somewhat unknowable threat, Dukat was a fascinating, deeply conflicted villain who used surgery to look like a Bajoran and seduce the ultimate space Karen, Bajor's religious leader, Kai Winn (Louise Fletcher). She was pretty shaken when she discovered that she was sleeping with her greatest enemy, but Dukat had already gotten enough information to bring about Bajor's prophesied end times by aligning himself with the "evil" entities of Bajor, the Pah-wraiths, who were Prophets (aka wormhole aliens) cast out from their timeless paradise. In order to stop Kai Winn from unleashing the Pah-wraiths upon Bajor and the rest of the Alpha quadrant using Dukat as a sacrifice, Sisko grabs him and they fall into the pits of the fire caves together. 

Sisko awakens in the white light of the Celestial Temple and is surrounded by the Prophets, taking on the shapes of people from his life so he can understand their messages. It's the same place he visited in the very first episode of the series when he learned that he was the Emissary. They tell him that he has to stay with them for a time and help them learn about what it is to be mortal. Unfortunately, that means leaving behind his young adult son, Jake (Cirroc Lofton) and his pregnant wife, Kasidy Yates-Sisko (Penny Johnson Jerald). He gets a chance to tell Kasidy where he's going using a psychic vision, but otherwise doesn't really get a chance to say goodbye. The hope is, of course, that he'll make good on his promise to Kasidy and return one day. 

At its core, "Star Trek: Deep Space Nine" is a series about the sacrifices people make in the name of doing the right thing. Sisko understood better than most that sometimes the right thing to do is the hardest thing, having sacrificed his self-respect in order to get the Romulans to join the side of the Alpha Quadrant in the battle against the Dominion. In the end, he sacrifices a life with his wife and children in order to help the Prophets and hopefully create a better future for everyone in the universe. He doesn't know how long it will take, because time isn't linear in the wormhole, but he does it anyway. Jake and Kasidy must sacrifice their time with Ben as well, and while they don't have as much of a say in it, they do have a choice in how they live with his sacrifice. 

Odo and Kira are also forced to make a great sacrifice when Odo returns to the Great Link, as it means they will likely never see one another again. They have a heartbreaking and tearful goodbye. After spending the entirety of "Deep Space Nine" having the worst taste in men, Kira finally found a good one, only to have him be tasked with completely re-educating his species. They sacrifice their future together willingly because it's the right thing to do. The finale is called "What You Leave Behind" because of what characters like Sisko and Odo leave behind: their lovers, family, friends, and previous lives. Their noble sacrifices will change the face of the galaxy, but not without leaving a great deal behind. 

The Dominion War was costly, with major casualties on both sides, but it helped some former enemies in the Alpha Quadrant learn to be allies. Major Kira is given a Starfleet posting as a special consultant to Damar and the Cardassian rebellion, a real irony since she once rebelled against the Cardassian occupation of her own world. She teaches them to use the very tactics she once used against them, and along with Deep Space Nine's tailor-slash-spy, Garak (Andrew Robinson), she manages to teach the Cardassians to fight dirty and really do damage to their mutual enemy. A kind of respect is forged among these extremely unlikely allies as they're forced to sacrifice their egos and former allegiances in the name of stopping the Dominion. 

Watching these characters grow throughout the series is truly something, as both Garak and Kira started with very strong personal beliefs and a lot of bitterness in their hearts, but they learned to work through their trauma and grow into incredibly powerful people. Kira ends up taking over Deep Space Nine in Sisko's absence, helping to forge a future in the Federation for Bajor and keeping the wormhole well-guarded. She has an incredible character arc that's one of the show's most powerful, and though she's lost so much, she also became a real hero for not only her people, but the entire Alpha Quadrant. 

There's a great moment in the finale before Sisko is pulled away by the Prophets and Odo goes back to his home world where everyone gathers at Vic's one last time. In the final two seasons, the crew of Deep Space Nine would get together in Dr. Bashir's 1920s lounge singer holosuite program, overseen by self-aware hologram Vic Fontaine (James Darren). Vic helped Odo first proclaim his love for Major Kira and also helped Nog (Aron Eisenberg) learn to overcome his PTSD after losing a leg in battle, making him so much more than just a hologram, and it's perfect that everyone gets to say their goodbyes there. It's more emotionally resonant than Quark's own bar, because several of the characters were initially resistant to Vic's musical magic, but in the end they all surrender to a tiny bit of technologically-assisted whimsy. Even perpetually grumpy Klingon Worf (Michael Dorn) shows a soft side here as he recommends that O'Brien and his family relocate to his hometown of Minsk, as they are moving to Earth for O'Brien to take a cushy job teaching at Starfleet Academy. 

It's a chance for not only the characters to say goodbye to one another, but for the audience to say goodbye to this crew that they've come to know and love over the course of seven intense seasons. Though there's lots of adventure and sci-fi allegory happening in "Star Trek," every iteration is also a bit of a hangout show because we want to tune in and spend time with the crew each week. The farewell at Vic's gave the "DS9" crew the same treatment as many sitcoms, allowing for some emotional closure to counteract the bitterness of so much sacrifice. 

Though there is a tremendous amount of change that happens at the end of "Deep Space Nine," the series also shows us that some things are still the same as they've always been. Quark is still the best-dressed person on the station and his number one customer, Morn, is still keeping his favorite barstool warm. There will be new challenges that face Kira and the rest of the crew, but they will have each other. Dr. Bashir has finally found love in Ezri Dax (Nicole de Boer), Worf signs up to be the Federation ambassador to the Klingon homeworld Qo'noS, and almost every loose end was wrapped up. (Unfortunately there weren't any flashbacks to Worf's late wife, Jadzia Dax, played by Terry Farrell, because of the circumstances of her character being written off the show, one of the only truly frustrating things about the finale.) 

There seems to be a real camaraderie among many of the stars of "Deep Space Nine," and many of them got together for a retrospective documentary on the series called "What We Left Behind: Looking Back at Star Trek: Deep Space Nine." In the doc, the writers of the series assemble to brainstorm a hypothetical season 8, continuing the story of Sisko, Kira, and the rest of the Niners. The idea was that it would start many years after the finale, and would feature Sisko's return from the Celestial Temple. While it's not canon, technically, it is a lot of fun, and it makes the idea of a live-action "Picard"-style reunion for the "Deep Space Nine" cast seem slightly more possible. 

"What We Left Behind" is a beautiful tribute to the series and gives some great insight into the making of the show, but it isn't the final piece of the "Deep Space Nine" puzzle. In season 3 of "Star Trek: Lower Decks," the ragtag crew of the U.S.S. Cerritos visit everyone's favorite ex-Cardassian space station, and fans got a canon update on the crew. Kira is still in charge, Quark is still mostly a giant nuisance, and Morn even makes an appearance, though we don't learn anything new about what's happened to Sisko, Odo, or any of the other characters who are missing for various fictional and real-world reasons. (Sadly, Auberjonois and Eisenberg have both died in the time since "Deep Space Nine" ended, meaning it would be impossible for Odo or Nog to ever return without recasting or using morally questionable technology.) 

While it's entirely possible that we'll never get a concrete answer on whether Sisko or Odo ever returned to their physically corporeal better halves, that's almost more fitting for the series anyway. "Deep Space Nine" was never a show about easy answers. It put its characters in situations no other "Star Trek" series would dare, and its ending helps the audience learn a little about sacrifice, too.