Unresolved Plotlines From Star Trek: Deep Space Nine

The "Next Generation" episode "Second Chances" introduces us to a duplicate of Commander William Riker, created during an unusual transporter incident that leaves the double marooned on a desolate planet for eight years. On a mission by the Enterprise back to the same planet, the other Riker is discovered and eventually takes the name of Thomas Riker, resuming his Starfleet career from the point he left off as a young lieutenant. Later, in the "Deep Space Nine" episode "Defiant," Thomas Riker turns up posing as Will Riker to steal the station's experimental new starship, the U.S.S. Defiant. It is revealed that after returning to Starfleet life, Thomas Riker became a member of the terrorist organization known as the Maquis and stole the ship to expose a Cardassian plot in the demilitarized zone. 

To stop him, Captain Sisko and Gul Dukat briefly join forces to hunt him down and stop him from destroying apparently innocent ships and jeopardizing peace with Cardassia. In the end, Thomas is apprehended, and in true Riker fashion, he negotiates to spare the lives of his crew in exchange for a life sentence in a Cardassian prison. Major Kira promises him they'll return to rescue him, but through the series' remaining four seasons, we never see that come to pass. Was he rescued by another Starfleet team? Was he killed when the Dominion turned on Cardassia? It's also possible that he was simply released after the Cardassians surrendered to the Federation. Whatever happened, if he did survive, it means there are still two Rikers running around in the world of "Star Trek: Picard."

First appearing in the Season 1 episode "The Wire," Garak is an enigmatic Cardassian — the last on the station — who was supposedly exiled from his homeworld and left to eke out an existence as a mere tailor aboard Deep Space Nine. Over the course of the series, we get drips and drabs of Garak's shrouded past: He was a spy working with the Obsidian Order — the Cardassian secret police and espionage agency — and an enemy of Gul Dukat. Apparently the son of the Order's leader Enabran Tain, it's never quite revealed why Garak was banished, though several possible explanations are offered up, including a few conflicting stories by Garak himself. Whatever the real reason, Garak made enemies in all corners of the Cardassian government, and when Tain died, he had seemingly lost his last best hope of returning to his home.

But as "Deep Space Nine" comes to a close and the Cardassians betray their Dominion allies, Garak is sent back to Cardassia. There, he and Major Kira go on a secret mission to aid rebel leader Damar, who helps the people rise up and take back the planet from the Dominion. Damar dies in his revolution, are Garak himself leads the final push to overthrow the Dominion. With Cardassian now free, it's suggested that Garak could be its next great leader. But it's never made clear, and for such a major turn for one of the show's most polarizing rogues, a definitive resolution to Garak's story was sadly missing.

The station's resident Changeling, Odo, begins the series as a character with an origin shrouded in the unknown. He doesn't know where he came from or if there are more of his people out there — all he knows is he was discovered in his gelatinous state floating in space by Bajoran scientists. And one scientist, Mora Pol, discovers that Odo is a sentient being and raises him to become the eventual constable aboard "Deep Space Nine." But in the 4th season premiere, "The Search," the Federation learns about the Changeling race who rule the Dominion called the Founders, and Odo finally finds his people.

The leader of the Founders would reveal Odo's origins too, and tell how — to gather information about the galaxy — their people sent a hundred such beings as Odo out into space. These beings lived amongst "the solids" and eventually returned to their homeworld to share all they had learned. The 7th season episode "Chimera" introduced us to Laas, another such Changeling, who tried to convince Odo to leave the station with him to seek their orphaned brethren and form their own metamorph society. But Odo declines, and we never learn what became of him, his quest, or the fate of the other 98 Changelings sent to learn about the galaxy. 

One of the darkest episodes in the pantheon of dark episodes of "Star Trek: Deep Space Nine," the O'Brien-centered entry "Hard Time," sees the chief convicted of a crime on an alien world and forced to experience 20 years of memories in prison in a matter of minutes. Doctor Bashir can't erase the memories, and O'Brien returns to duty a changed man: angry, short-tempered, bitter, and haunted by more than just his imprisonment. He begins to hallucinate the image of an alien named Ee'char, who acts as his conscience, and over the course of the episode, we learn that the implanted memories include O'Brien murdering his best friend and virtual cell mate over a few scraps of food. 

Most of "Hard Time" deals with the mental struggle that O'Brien goes through during his recovery from imprisonment and his fight to reclaim his former identity. It's a powerful episode with a lot of important things to say about mental health and PTSD. Unfortunately, despite the often serialized nature of "DS9," O'Brien goes right back to his old self by the following episode. Apparently suffering no lingering effects, what could have been a longer, ongoing subplot about his attempts to recover from his life-altering experience in prison is instead quickly forgotten. With "Star Trek: Picard" revisiting his time as a Borg and the long-lasting trauma it created, perhaps we may revisit O'Brien's struggle at some point in the future.

If you or someone you know is struggling with mental health, please contact the Crisis Text Line by texting HOME to 741741, call the National Alliance on Mental Illness helpline at 1-800-950-NAMI (6264), or visit the National Institute of Mental Health website.

The holographic lounge singer named Vic Fontaine first shows up in "His Way," an episode that sees Major Kira and Constable Odo finally getting together after years of the classic television "will-they-won't-they" trope. In the story, he's introduced as something more than a holodeck character, but something not quite as sentient as The Doctor over on sister series "Star Trek: Voyager." He becomes the conscience of the show for the last season and a half, and it's made clear by Bashir that Fontaine is a "unique" program. And if Voyager's Doctor gained sentience through his long hours online — something heavily suggested in several episodes — it's possible that Fontaine gained personhood in the same way after being left on round-the-clock in "It's Only a Paper Moon." 

If Fontaine is indeed more like a real person than other pre-programmed holographic characters, it's also possible that after the arrival of the starship Voyager to the Alpha Quadrant at the end of their series, he could have been fitted with his own mobile emitter and allowed to walk free of his holosuite confines. But we're never quite told whether Fontaine is a sentient program or just an elaborate one. Of course, this one's a double dangling plot, as Vic Fontaine also made a brief cameo in the mirror universe episode "The Emperor's New Cloak." Here, his alternate reality counterpart at least appears to be a real person before he is unceremoniously killed in another mystery that the show never solves.

No Trek fan can possibly be satisfied with the fate of Benjamin Sisko at the conclusion of "What We Left Behind," the final episode of "Star Trek: Deep Space Nine." In some ways, it was the perfect conclusion for the character's seven-year-long journey from Starfleet commander to Emissary of the Prophets, as he sacrifices himself to end the threat of the Pah-wraiths. But after the captain becomes a non-corporeal entity residing in the Celestial Temple, the writers throw in one tantalizing line at the end of his final moments, teasing audiences of his possible return.

Before beginning his life as a Prophet, Sisko speaks to his wife Cassidy one final time from inside the Celestial Temple and tells her he has much to do. There are things he must learn that only the Prophets can teach him, he tells her, but before he vanishes, he promises her that he will return. When she asks when that might be, he's vague, saying only, "It's hard to say. Maybe a year. Maybe yesterday. But I will be back." It's a pretty declarative statement and must have made fans wonder if there were plans afoot for the series to make the move to feature films, or perhaps a TV mini-series follow-up somewhere down the line. Given actor Avery Brooks' disappearance from acting, however, any thought of revisiting Sisko's story seemed unlikely until recently, when rumors began circulating that he might be interested in reprising the role.