Star Trek has been the paragon of science fiction stories for decades. Every series has brought adventures well known for their excitement, poignancy, and intellectualism. In the earliest days of Star Trek, networks were uncertain about the franchise's cerebral approach to sci-fi space exploration.
However, the stories and characters have kept us coming back season after season to see how Picard will tackle a complex alliance, how Sisko will handle the latest threat, or how Janeway will get her crew home to the Alpha Quadrant. These much-beloved stories are near and dear to the hearts of fans, but there are many stories of those crews we never got to see.
In the process of developing many seasons of content, some episodes got stuck in development because of controversial content, effects on the rest of the series, or the limitations of the time. Although parts of these episodes sometimes get reformed into new episodes, these adventures and plot twists never saw the light of day.
These undeveloped episodes would have brought back fan favorite characters, sparked shocking revelations about familiar characters, and brought fans through mind-boggling adventures. If some of these episodes had been produced, they would have changed the face of Star Trek forever.
Here are the 20 Canceled Star Trek Episodes We Never Got To See.
20 Return of Spock (Enterprise)
The Enterprise writers enjoyed many of the benefits of being a prequel, including bringing back younger versions of beloved characters. At one point, the writers were trying to get Leonard Nimoy to guest star in an episode to kick off a two-part episode about old T'Pol and the rest of the Archer crew helping young Spock on a mission.
Writer Mike Sussman described in a memo about the episode, "The flashback adventure should involve Captain Archer (and other members of our cast) in old-age make-up, playing early 23rd century versions of themselves."
"Maybe their adventure is something of a 'Last Round-Up' for the old crew, whom T'Pol reunites for a secret and possibly illegal TBD mission. I thought it might be fun if our crew have to steal an antiquated NX-class ship from the Starfleet museum for one last adventure together," he said.
19 Undeveloped Q Episodes (TNG)
Q is easily one of the most beloved characters in all of Star Trek, constantly showing up to mess with Starfleet's captains and cause chaos. Q almost had several more adventures in The Next Generation.
In "Q Makes Two", Q tries to prove to Picard the humans need both their good and evil components by splitting the Enterprise crew into doubles, one good and one dark. Q makes the two crews confront each other and it's clear that neither crew can function without the other.
In "I.Q. Test", Q makes a wager with another Q that leads to a deadly Olympics-like contest between the Enterprise crew and the Zaa-Naar, a dangerous alien species.
In another undeveloped episode, Q loses his mind, causing reality to turn ludicrous. The crew must figure out that reality has changed and turn to Q, who is shown as a seemingly insane homeless man.
18 Janeway on Trial (Voyager)
Writer Ron D. Moore pitched a story that would have had the crew of Voyager deciding the fate of Captain Janeway.
Moore explained, "When we were talking story before the season began, I thought, 'One of the shows you should do is the trial of Captain Janeway. You should have the crew, one day, put her on trial.' That would be a real major thing in [the] life of the ship, if the crew can do that, if they really have the power to take command away from her at any moment."
He added, "If they are really willing to put her under that kind of microscope, it calls into question the entire structure of the show, the entire social fabric, the command structure. Why are we behaving in this way? Why do we hew to these rules anymore? Do the rules still apply to us?"
17 Tomorrow Was Yesterday (TOS)
In the Original Series, the planned two-part episode "Tomorrow Was Yesterday" would have thrown the Enterprise into the middle of a strange consequence of space travel.
The episode would have revolved around the Enterprise crew discovering a relic ship, a forgotten generation ship launched from Earth long ago. The crew soon discovers the ship's inhabitants have forgotten why they are aboard the ship, and they do not know there is anything beyond the ship's walls. Within the ship, two factions are fighting for control.
Producers liked the episode, but decided it was far too expensive to produce on their television budget, stating it would be ideal for a multimillion dollar movie budget. However, the episode's writer, David Gerrold, did later turn the plot into a Star Trek novel.
16 Crash of the Enterprise (TNG)
Ron D. Moore and Brannon Braga worked on a two-part episode that would have ended the sixth season of The Next Generation in a dramatic twist. In this episode, the Enterprise is recalled to Earth, and the crew is dispersed and assigned to new posts.
On the return journey to Earth, as the crew decides what to do with their lives, the Enterprise gets into a battle with an alien ship, separating the saucer section from the ship. The saucer section crashes on an alien planet, and the Enterprise is lost beyond repair.
Braga claimed the writing staff had been wanting to destroy the Enterprise-D in order to give the final season a new ship and a new style. The idea was rejected, as movies were planned following the conclusion of the series, and the producers wanted the familiar ship for the transition.
15 Great Escape (DS9)
The Deep Space Nine writers had long been toying with writing a version of The Great Escape, focusing on an elaborate prison break. Although they eventually did a similar plot in the two-parter "In Purgatory's Shadow" and "By Inferno's Light", the original version looked very different.
The original plan was to focus on Michael Eddington, the Maquis agent and disgraced Starfleet security officer. Producer Ira Seven Behr explained that the episode would follow Eddington "with him in the brig and showing how he breaks out, forcing the audience to kind of root for the guy. It never worked out, because we weren't confident that the fans were really behind the character."
The plan to focus on Eddington was abandoned, but the basic plot was kept for the fifth-season episodes.
14 The Squaw (TOS)
Star Trek seemed to love planets with parallel Earth evolution, but one planned episode would have involved the Vulcans, as well.
"The Squaw" would focus on a lost colony of humans who set up their society based on the tropes of a third-rate pulp Western novel left by their ancestors. This planet was also inhabited by Vulcans in a "primitive" state, unlike the logical Vulcans that Spock and the Enterprise crew knew.
The Vulcans regularly attack the human colony. Later, the crew discovers that the Vulcans were peaceful until the humans harassed and hunted them, treating them as the Native Americans were treated in the Western novel.
The ideas of this episode would surface in "A Piece of the Action" with gangsters in place of the Western cowboys.
13 Mirror Universe (Voyager)
The mirror universe has been a fun concept in Star Trek since the Original Series. Not all of the series got to explore the concept, but Voyager almost did.
Writer Bryan Fuller described, "We'd follow the crews of several alternate Voyagers. There was a Klingon crew with a 'Mistress Jan'toch' – Captain Janeway in Klingon make-up ... a holographic crew that was essentially The Doctor to the infinite power, and several others. In each of these instances, some unseen force would destroy the alternate Voyager and its crew."
He continued, "Ultimately, the real Captain Janeway and her posse would discover that another alternate Voyager with a twisted Chakotay in command was responsible. He was from a universe where the Maquis overthrew the Starfleet crew. He had a personal vendetta against Janeway and Voyager, and wouldn't stop until he had snuffed each and every one of them out of existence."
12 Porthos (Enterprise)
Some characters never got the screen time they deserved, like Captain Archer's adorable beagle Porthos. Producer Andre Bormanis claimed that Porthos almost had a much larger part in an episode, with a few Porthos-centric ideas in consideration.
Some of these plotlines included Porthos gaining intelligence, Porthos being able to communicate with a canine alien that no one else could communicate with, and even Porthos taking command of the ship.
The dog's handler also claims there was an idea to have Porthos in a transporter accident where he changes sex to explain why he's played by a female dog. It was never certain if these ideas were real episodes in consideration or if they were joking when they made these claims, but let's be honest - we'd watch it.
11 Return of Chekov (TNG)
The Next Generation brought back several popular Original Series characters for a guest starring role, but one that ultimately fell through was the return of Chekov.
Walter Koenig, who played Chekov, came up with an idea to have Chekov as a hallucination who was not actually there, possibly hallucinated by Worf.
Story Editor Naren Shankar had a different idea, stating, "I was working on a Chekov story where he returns as a prisoner-of-war from a planet where he was imprisoned for many years and finally released."
"Now he has come back as an ambassador to help the Federation open up diplomatic relations, like Vietnam, essentially. The story was going to be about Worf and Chekov ... It turns out [Chekov] is plotting to ... screw things up for the Federation because he feels they abandoned him and let these people torture him," he said.
10 Deep Mudd (TOS)
The Original Series writers and producers kept trying to bring back Harry Mudd. After the events of "I, Mudd", Mudd would escape Planet Mudd and get entangled in yet another sticky situation.
Writer Steven Kandel elaborated, "'Deep Mudd' involves Mudd's escape from that world, after he tricked these particular robots into revealing to him the location of a cache of scientific equipment and weaponry left by their makers. Suddenly Mudd found himself with very, very advanced armament, which he used to bribe a group of pirates into helping him escape."
"The problem was, of course, that he could control neither the weapons nor the real heavies he was supposed to be in control of, the pirates. They tangled with the Enterprise ... That was basically it: bailing Harry Mudd out of his own problems, getting control of this weaponry they couldn't destroy, and sending it into a sun," he explained.
9 Cold and Distant Stars (DS9)
"Cold and Distant Stars" would have shown Captain Sisko waking up in 1995 Santa Monica, disoriented but still aware of his identity.
Writer Robert Wolfe explained, "I wanted Sisko to be saying, 'I'm the captain of a starbase in the year twenty-three-whatever, and I don't belong here.' And everybody's telling him, 'You're a homeless schizophrenic, take your Thorazine.'"
Writer Rene Echevarria added: "Sisko would see a cop and it would be Rene Auberjonois without his makeup. The homeless counselor would be Dax without the spots. Sisko would be seeing these blurry things and realize he was seeing through some weird filter."
Wolfe continued, "The idea came from the fact that my wife has been a counselor for the mentally ill homeless for a long time, and I've learned that just because they say they are something they couldn't be, doesn't mean it's not true for them."
8 Korath's Revenge (Enterprise)
Admiral Janeway left a lot of loose ends in her wake when she traveled back in time to get Voyager home earlier, and one of those loose ends almost became very important.
Admiral Janeway obtained her time machine from the Klingon Korath. When Korath tried to change the terms of agreement on Janeway, she stole the time machine he developed.
Star Trek veteran Vaughn Armstrong, who played Korath and many other characters, pitched an idea that would have brought Korath's wrath down upon Starfleet.
Armstrong stated, "An episode I would love to see would show Korath taking the time machine that Janeway stole from him and going back to stop Admiral Forrest from sending people out into space." He said Korath would steal the machine back from Janeway and attempt to stop the NX-01 launch shown in the Enterprise pilot.
7 Blood and Fire (TNG)
The episode "Blood and Fire" by David Gerrold would have been an allegory for the AIDS epidemic that was a serious problem at the time, but the episode was canceled due to controversy.
Gerrold explained, "I knew that people were so terrified of AIDS they had even stopped donating blood. So I wanted 'Blood and Fire' to be about the fear of AIDS – not the disease but the fear – and one of the plot points involved having the crew donate blood to save the lives of the away team."
"I thought, 'If we do this episode right,... we can put a card at the end telling viewers that they could donate blood to save lives, too.' I thought it was something Trek should be doing, raising social awareness on an issue, and ... we could probably generate a million new blood donors at a time when there was a critical shortage," he said.
6 Home (Voyager)
The writers of Voyager often wanted to delve into different ideas to try to speed up Voyager's journey, and "Home" was B'Elanna's attempt to shorten the trip.
Writer David Steinberg explained, "Wanting to prove her worth as an engineer... B'Elanna theorizes that a multi-phasic tachyon generator could generate an artificial wormhole to get them home in one jump."
"But when she convinces Janeway to try the new device, it works, a little too well ... sending them billions of light years to another galaxy on the other side of the universe. No Federation ship has ever ventured outside our own galaxy, and this distance would take literally millions of years at top warp. The galaxy they've traveled to is far older than our own ... and therefore devoid of life as we know it," he stated.
Later in the episode, they realize they are in their own galaxy, billions of years in the future.
5 Sister in Space (TOS)
Star Trek had many intense episodes, but it was rarely outright terrifying. The planned episode "Sister in Space" would have been very different. The outline reportedly almost gave one producer a heart attack.
The episode involved the Enterprise discovering the long-lost USS Yorktown dead in space. Kirk, Scotty, Sulu, Rand, and assorted redshirts beam aboard the ship and find themselves trapped and pursued by a lethal alien creature that killed the Yorktown crew.
The creature possesses enormous strength and a chameleon ability that allows it to blend into its surroundings. The creature begins to pick off the redshirts, tearing them limb from limb.
Producers decided it was too expensive to produce an episode that was basically an early Alien or Predator, and the episode was dropped.
4 Geordi's Reveal (TNG)
Geordi LaForge was far too often relegated to the background of the plot on The Next Generation, but one story concept would have made Geordi the crux of a major twist.
In the planned episode, Geordi would have discovered he was the product of an alien experiment that involved his mother.
Producer Jeri Taylor explained, "We wanted to make Geordi an alien. He was going to discover that his father was not who he thought he was, and his mother had an almost Rosemary's Baby-kind of thing and had been impregnated by an alien."
"As a result, Geordi was actually half alien and now, at his present age, his people were coming back to get him. I thought that would have given Geordi's character a lot of elaboration," she said.
3 Musical Episodes
Although musical episodes now seem to be everywhere, Star Trek was almost early on the trend by creating a musical episode as far back as the '80s.
Writer Ronald D. Moore pitched a musical episode for The Next Generation, but no other writers got on board with the idea. Years later, Moore and producer Brannon Braga agreed they could have made it work by using the holodeck.
Moore continued to push for a musical episode when he went to write for Deep Space Nine. Moore stated, "I was agitating for a musical, man. On record, I wanted to do a musical version of Trek well before Buffy or Chicago Hope. I wanted to do a musical episode, and nobody would f***in' do it."
He explained about the potential excuse for the episode, "There's just some tech virus that infects the crew and they can only communicate in song."
2 Portrait in Black and White (TOS)
The Original Series never shied away from controversial subjects like race, but one episode proved too difficult to handle.
The episode involved the Enterprise coming upon a planet with parallel development to Earth in America's plantation days, but with the racial roles of black and white reversed. The planet was controlled by black traders who sold white "savages" on the slave market.
Writer Stephen Kandel explained when the Enterprise arrived, "The only one they would talk to was Uhura, and they regarded the others as nothing." DeForest Kelley was fond of the story and hoped it would feature McCoy and Uhura, creating interesting dynamics with his own Southern heritage.
The network shot down the concept, but Gene Roddenberry was ready to fight the network. The episode went through several rewrites, but the script was never developed into a workable form. Given the lack of network support, the writers dropped it.
1 Homecoming Invasion (Voyager)
As early as the third season, Voyager writers were planning a dark twist on Voyager's homecoming.
Producer Jeri Taylor explained, "Everybody thinks that Voyager is home and there are celebrations, and they see their loved ones, etcetera, etcetera. And it turns out to be an invasion or a dark plot of some kind."
Writer Joe Menosky continued, "Brannon [Braga] had some great images. One was opening with Voyager above Earth, this great homecoming sequence. There are fireworks in the sky, and everybody is going down to their homecomings."
"Janeway has a wonderful tearful reunion with Mark. She kisses Mark and she then snaps his neck, end of teaser. Then he had this image of like a thousand Voyagers converging on Earth. Somehow, these duplicate Voyagers were being created that didn't even know who they were," he said.
Ultimately, writers decided the story would rob too much from Voyager's real homecoming.
Can you think of any other Star Trek episodes that were canceled? Do you wish you could have watched any of these? Let us know in the comments!