Of all the Star Trek spin-offs, Star Trek: Deep Space Nine was characterized by its distinct format, an amalgamation of the episodic Next Generation and the now narratively progressive Star Trek: Discovery. Full of intense drama, political intrigue, and mature themes, DS9 was known to push the envelope in not only the Star Trek franchise but the sci-fi genre as a whole. Its tone and narrative style would inspire many series hoping to duplicate its success.
Given that it was less about space exploration aboard a starship and more about interpersonal relations between humans and alien cultures on a space station, it was unlike any previous incarnations of Star Trek. But as the series explored the psychology of its characters and their moral imperatives through a linear storyline in the later seasons, it faced problems concluding arcs given that each episode wasn't self-contained. Here are 10 Deep Space Nine storylines that were never resolved.
During a freak accident involving the transporter on Next Generation, Commander Riker gets copied. This “clone” assumes the name Thomas and gets outfitted with a golden uniform to tell himself apart from his original. Thomas Riker would later go on to make his way in the galaxy, eventually ending up on Deep Space 9.
He would go on to join the Maquis, steel a ship from DS9 while posing as Will Riker, and take Major Kira with him to spy on Cardassian war fleet development. He was captured by the Cardassians, and that was the last we saw of Thomas Riker. Kira said she would come back for him one day, so... did she? Or did he sit out the entire Dominion War in a jail cell?
During the first season of DS9, Benjamin Sisko meets Kai Opaka, the spiritual leader of the Bajoran people. She senses an extreme spiritual mindfulness in Sisko and departs his presence with this line of dialogue, “My work is here now, Commander. But your path and mine will cross again.”.
Considering that Sisko later becomes a time-traveling demi-god of sorts, it’s possible that they would meet again, but that set up in the first season seemed to imply their meeting would be of some import when it happened (not just in one of his visions). If the Opaka helped the Ennis and Nol-Ennis, they might have become an ally in the Dominion War.
Throughout Star Trek: The Next Generation, Starfleet butt into the business of the Enterprise-D whenever it stumbled upon unique technological discovers that Starfleet thought might be useful down the line (Data’s “offspring” Lal, Data himself, etc). In the last season of DS9, a piece of technology is introduced that seems extremely useful to Starfleet but is never mentioned again.
An insane Vulcan has begun murdering people on the station using a heavily modified TR-116 assault rifle. It’s a modified projectile rifle that has a scanner and a micro-transporter it can scan through bulkheads and “transport” a bullet into the vicinity of whomever the shooter is attacking. The Vulcan could kill people from anywhere on the station without a trace! This is never used to develop weaponry against the Dominion for some reason.
Worf coming to DS9 in the middle of its run was both necessary and problematic. His presence provided a solid connection to Next Gen, and therefore franchise cohesiveness, but his character was different enough from his time on the Enterprise-D that some of his storylines in DS9 made fans scratch their heads.
In the episode “Tacking Into The Wind," he kills Chancellor Gowron, the de facto leader of the Klingon Empire, so that he can put his candidate in power. All the while serving on Starfleet he wasn’t allowed to commit suicide or honor and/or revenge killings against fellow Klingons because it’s against Federation law, yet there are no repercussions.
Though the Ferengi plots of DS9 often existed for comic relief or to enhance a preexisting storyline for the personnel on the station, there were occasionally serious repercussions for what the Ferengi meddled with beyond their own species.
In “Profit and Lace," Quark doesn’t just impersonate his mother to discuss gender equality with Ferengi females—he undergoes complete gender reassignment surgery, which Dr. Bashir facilitates without question. Is the Federation so in favor of changing Ferengi attitudes and treatment of women that they sanction it? Even if they don’t agree with the way a species lives, the Federation doesn’t force its mindset on them, as that would violate the Prime Directive.
The personnel of Deep Space 9 were probably incredibly grateful that they had Odo on their side, as having a Changeling on the side of the Dominion was a terrifying prospect. In Season 5, it was revealed that Dr. Bashir was actually a Changeling spy, the real Bashir having been kidnapped by the Dominion along with a cadre of other prominent delegates.
The whole incident prompts Starfleet to start testing the blood of all its members, but nowhere is it explained just how many other Dominion operatives might have infiltrated it. No doubt, like with the “Conspiracy” parasites of TNG, they got to high-ranking members as well in hopes of turning the tide of the war.
The debate about “should they or shouldn’t they have” closed the wormhole has been brought up many times in the wake of the Dominion War and the end of DS9. The Federation was shown as an organization that would do anything to end of the war, yet they wouldn’t do the one thing that would have saved the most lives.
Back in Season 4, it was established that shooting graviton and chroniton particles into the wormhole would cause it to close, thereby preventing the Dominion from passing into the Alpha Quadrant for at least several decades. Why didn’t they do this before the Bashir impersonator strengthened the wormhole? It would have prevented the Federation from sending its people into battle without energy shields, battle weapons, or armor like a bunch of red shirts to the slaughter.
In one of the most intense DS9 episodes, Miles O'Brien is punished for supposed espionage by getting 20 years of jail time implanted into his brain. He can never remove these memories, and Miles struggles to reconcile the experience with being re-integrated into his life on the station despite his trauma.
The episodic nature that plagued Next Gen took hold in “Hard Time," as, by the next episode of DS9, Miles had seemingly forgotten all about the hardship he faced in the previous one. But it’s not the sort of plot that can be wrapped up at the end of an hour. But the extreme emotional duress never comes up again, or even affects his demeanor, despite the fact that he was suicidal.
Benjamin Sisko went through quite the transformation during DS9, from military leader and Starfleet commander to spiritual guide and prophet. By the series end, he had followed in the footsteps of his mother, becoming a being that existed outside linear time, enabling him to potentially reunite with her one day.
The weakest point of a phenomenal last few seasons occurs when we don’t find out exactly what happened to Sisko, if he ever met up with Kasidy, or if he ever went through the wormhole. If he had, he would position himself in the past, which would have opened up a whole series of opportunities for him (i.e., could he go back and prevent the Borg attack that killed his wife?).
After the Dominion War is over, life presumably returned to some level of normalcy for Deep Space 9 and the rest of the Alpha Quadrant as the Federation and Starfleet rebuilt. Though it’s not explicitly stated, the treaty the Dominion were forced to sign no doubt stated that they could never come through the wormhole again, and couldn’t harass any ships that went through it.
The Federation would never sanction some sort of occupation in Dominion Space, especially since it could even be larger than Federation Space, to say nothing of the moral implications. Still, we can always wonder the fate of the Dominion, as well as what happened to the Cardassian Empire.