In his book, Trek: The Unauthorized Behind-The-Scenes Story of The Next Generation, James Van Hise explored several unfilmed or unproduced episodes written for Star Trek: The Next Generation, most notably the controversial episode, written by Gerrold, entitled "Blood and Fire".
During the seventh season of TNG, Joe Menosky pitched a story in which Alexander Rozhenko accidentally fell into a time portal and permanently aged into a bitter twenty-five year-old. According to René Echevarria, Menosky greatly disliked the character, and saw this as a way to "get rid" of him. Echevarria recalled, "In that story, Worf and Alexander were on a hunting trip and Worf loses sight of his son for a second. Alexander goes through some kind of portal, winks out, and then a second later he walks out and we learn that he's been in a world where fifteen years have passed. He's now a grown man and a warrior and he has great resentment toward his father because he doesn't understand what happened." (Star Trek: Deep Space Nine Companion, p. 577)
Michael Piller repeatedly quashed the idea. Ronald D. Moore noted, "Michael shot it down time and time again." According to Echevarria, "We never did that show because Alexander was Michael Piller's mother's favorite character." (Star Trek: Deep Space Nine Companion, p. 577) Piller has offered a different explanation, maintaining that "I just thought it was a nasty thing that we were basically taking the kid's entire childhood away. I just wouldn't go for it." (Captains' Logs: The Unauthorized Complete Trek Voyages, p. 303)
While the premise remained unused on TNG, it inspired the idea of having a time-traveling Alexander in "Firstborn". (Star Trek: The Next Generation Companion 2nd ed., p. 292) Echevarria kept the story in mind after moving to Star Trek: Deep Space Nine, and it was eventually developed (after much resistance from Ira Steven Behr) into the sixth season episode "Time's Orphan", with Molly O'Brien in place of Alexander. (Star Trek: Deep Space Nine Companion, p. 577)
A story pitched by Nick Sagan was to have featured a return of the character Armus, from TNG: "Skin of Evil". (Captains' Logs: The Unauthorized Complete Trek Voyages, p. 293)
Blood and FireEdit
"Blood and Fire" was a controversial episode written by David Gerrold which allegedly involved gay characters and an allegory on AIDS. The rejection of this episode is what partly led to Gerrold leaving TNG.
In a 2011 interview, Gerrold concurred: "my cause at the time was blood donorship, and 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, where blood donorship is part of solving the problem, 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 if we did it right, we could probably generate a million new blood donors at a time when there was a critical shortage."
"There were two characters who were not very important to the story, but they were the kind of background characters you need. At one point Riker says to one of them, "How long have you two been together?" That was it. The guy replies, "Since the Academy." That’s it. That’s all you need to know about their relationship. If you were a kid, you'd think they were just good buddies. If you were an adult, you'd get it. But I turned in the script and that's when the excrement hit the rotating blades of the electric air circulation device. There was a flurry of memos, pro and con. One memo said, "We’re going to be on at four in the afternoon in some places and we’re going to get angry letters from mommies." My response was, "If we get people writing letters, it shows they’re involved in the show, and that’s exactly what we want. We want them engaged, and a little controversy will be great for us." And I said, "Gene made a promise to the fans. If not here, where? If not now, when?" But the episode got shelved anyway and that’s when I knew I wasn't going to be allowed to write the very best stories we should be writing. The original show was about taking chances. If we weren't going to take chances, we weren't doing Star Trek. So I let my contract expire and I went off to do those other things I told you about." 
Blood and IceEdit
"Blood and Ice" was Herb Wright's second draft of Gerrold's "Blood and Fire". Wright kept the same basic adventure, but removed the allegedly gay characters and the AIDS allegory, replacing them with zombie crewmen. Despite the rewrite, this version remained unfilmed as well.
"Charlie X" storyEdit
A sequel to TOS: "Charlie X", featuring the character Charles Evans, was pitched by Nick Sagan. (Captains' Logs: The Unauthorized Complete Trek Voyages, p. 293)
Children of the LightEdit
"Children of the Light" was written by Michael Okuda
The Crystal SkullEdit
"The Crystal Skull" was written by Patrick Barry
Dead On My FeetEdit
"Dead On My Feet" was written by Richard Krzemien, draft date 19 November 1987. (The Making of the Next Generation From Script to Screen - Part Two)
- "I wrote the story in 1987 at the behest of a mutual friend of Gerd Oswald. Oswald had directed a couple of Star Trek episodes in the sixties ("The Conscience of the King", "The Alternative Factor") and I'd spoken to him while he was directing an episode of the new Twilight Zone for CBS when I visited that studio in 1986. Oswald was looking for a story he could take to Paramount for The Next Generation which he could attach himself to as the director. He read this outline but rejected it as being "too depressing." I told my friend that Gerd, who was then in his seventies, was obviously a man who had never come to terms with his own mortality. Gerd Oswald died two years later of cancer."
Derelict creature story Edit
During his time on The Next Generation, David Kemper pitched a story which was described by Rockne O'Bannon as follows:
- "The Enterprise comes across a ship that seems to be derelict. Their people go on board and the ship is empty, but the walls have this kind of slime on them, which they discover is actually a creature like a hermit crab, which takes over the ship and lives within it. When it gets larger, it has to find a bigger home, so now it heads for the Enterprise."
This story was never produced, but when Kemper became a writer for Farscape he recycled the idea, with a number of changes in the concept, and it eventually became the first season episode "Through the Looking Glass". (Farscape: The Illustrated Companion, p. 68)
Following his work on "Transfigurations", René Echevarria was asked by Michael Piller to work on an environmental story for the show. Echevarria recalled, "I came up with something for which I wrote many, many drafts, but it never got off the ground. Towards the end of that process, he said he had a script that he wanted me to write. It involved every environmental story that people had done and seemed fairly obvious. They in fact commissioned a teleplay that was literally smokestacks, and it would have been very obvious to the audience that it was the cause of the blindness and mutations in a tribe that was kept on a little island called the Island of Tears. They were kept there, hidden from view, in order for the rest of the society to be able to maintain its mode of production, which was highly exploitive and environmentally unsound. The audience would have guessed at the end of the first act what was going on. What I came up with was a Federation colony that mined dilithium and they're natives to the planet. The twist was that what was causing the problems were these organisms that had evolved in the presence of electromagnetic fields of dilithium. Its removal was creating mutations." (Captains' Logs: The Unauthorized Complete Trek Voyages)
"Ferengi Gold" was a second season two-parter written by Gene Roddenberry. The story would have involved a combination of some of Roddenberry's favorite themes: alien worlds developing civilizations very similar to those of Earth, aliens (in this case, the Ferengi) utilizing superior technology to appear godly, attractive women appearing for no good reason, and the moral perfection of the Federation. The concept of Ferengi posing as gods would be used, years later, in "False Profits". (Star Trek Monthly issue 26, p. 27)
Lisa Klink, who later went on to write stories for Deep Space 9 and Voyager, started her association with the franchise by pitching a The Next Generation story under the open submission policy. In the story, Geordi thanks to his visual implants was the only crew member able to telepathically communicate with an alien race. However, this proved emotionaly entensive and "way out of his engineering comfort zone". The story was not accepted, but earned her an invitation to pitch for Deep Space 9, starting her Star Trek career. 
The Hands of TimeEdit
"The Hands of Time" was written by Ken Gildin.
The Immunity SyndromeEdit
The Kreen Legacy Edit
"The Kreen Legacy" was a two-parter and written by Larry R. Butcher.
The Lost and the LurkingEdit
"The Lost and the Lurking" was written by Robert Wesley.
The May FlyEdit
"The May Fly" was written by Richard Krzemien, draft date 1 October 1987. (The Making of the Next Generation From Script to Screen - Part Two)
The Neutral ZoneEdit
An unproduced Romulan story, also featuring aspects that made their way into "Too Short a Season", was entitled "The Neutral Zone". It was completely unrelated to the later "The Neutral Zone". Scripted by Greg Strangis, the story featured famous Starfleet security expert Billings, who, confined to a wheelchair and clearly distant and lonely, had led the mission which had rescued Natasha Yar from her brutal home world. Yet in spite of Yar's efforts to better make his acquaintance, he is completely oblivious to her attempts. Billings' mission is revealed in short order: the Enterprise is to take part in a trade negotiation which will involve, for the first time, the Romulan Empire. Picard's mission will be to get the Romulan delegates there, and Billings is on hand to assure that all goes well.
To implement this, he compiles a list of all Enterprise personnel who have had contact with Romulans, and orders that they be dropped off at a starbase for the duration of this sensitive mission. Ironically, this group includes the inveterate Romulan-hating Worf, whom Picard defends; Worf manages to remain on board, where he becomes involved in the obligatory Wesley subplot. Meanwhile, Beverly proposes an operation involving fluid drawn from Data's spine to help Billings who brusquely declines.
Romulan commander Gar, obviously against the accord he has been assigned to promote, beams aboard and dissension ensues. Matters grow complicated when the transporter malfunctions while the rest of the Romulan delegation is beaming over; after some tense moments, they are safely returned to their own ship, but Gar is less than pleased, especially when Data discovers a sabotaging device inside the transporter controls console.
Unfortunately for Wesley and Worf, their separate subplot took them, without authorization, into the transporter room; this does not bode well for them until Tasha turns up with security tapes, showing Gar inserting the device. The Romulan remains insouciant, claiming that the negotiations were leading to disaster anyway and that his actions were merely getting the problem out of the way quicker. With all this sorted out, Billings consents to Dr. Crusher's proposed operation, and is able to walk. (Trek: The Unauthorized Behind-The-Scenes Story of The Next Generation)
It is interesting to note that a passing reference by Picard to an engagement with a Romulan ship sometime in his career is inconsistent with the history of Romulan isolation as described in the actual episode.
The One and LonelyEdit
"The One and Lonely" was written by Richard Krzemien, draft date 18 June 1987. (The Making of the Next Generation From Script to Screen - Part Two)
Season 5 Q storiesEdit
During the fifth and early sixth season of The Next Generation, the writing staff struggled with two premises using Q that were both ultimately rejected, leading to an unintentional season-long absence of the recurring antagonist.
Q Makes TwoEdit
In "Q Makes Two", Q would have duplicated the Enterprise and the crew according to some uniform characteristic. Brannon Braga recalled, "There was a sense of doom from the moment we started 'Q Makes Two.' I think we broke it three times. René wrote two drafts and it was ultimately abandoned. It's an interesting notion that Q comes on board and Picard's saying people are inherently good and we have managed to get rid of our darker elements in the 24th century and we're better people. Q says, 'So you don't think you have dark components and you think you're better without them, well I'm going to show you a thing or two,' and so he extracts the darker components and puts them into doubles. The clean, good components suffer and so do the darker components and neither functions without the other. We see that dramatically, but for some reason we made it more complex than it needed to be. It's a show that could still work. The image in my mind that we never really got to was the two Enterprises shooting at each other, that's what you want to see."
Jeri Taylor added, "'Q Makes Two' was a debacle and it plunged us into a nightmare of having to get "Man of the People" ready." (Captains' Logs: The Unauthorized Complete Trek Voyages)
According to Taylor, the idea of splitting a starship in two would later inspire the Star Trek: Voyager episode "Deadlock". (Captains' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages)
The plot also notably resembles the original series episode "The Enemy Within", except with the entire crew duplicated, rather than just the captain.
In the other scrapped premise, entitled "I.Q. Test", Q would have had a wager against another member of the Q Continuum that would have led to a deadly contest between the crew and the Zaa-Naar, a dangerous alien race. (Star Trek Monthly issue 26, p. 27) In fact, Q would have used the crew in a sort of Olympics against the other Q, and the Zaa-Naar would have been the other Q's chosen race of supermen. (AOL chat, 1998) The episode was based on a story by a new writer and involved input from Herbert J. Wright. (Star Trek Monthly issue 26, p. 27) However, the story was scrapped on account of Michael Piller. Ronald D. Moore later remarked, "In defense of Michael, the Q-Olympics story was ludicrous and needed to be deep-sixed." (AOL chat, 1998)
Despite rumors that Arnold Schwarzenegger would have appeared in the episode, Ronald D. Moore clarified, "There was never – ever – any chance that Arnold was going to appear on the show." (AOL chat, 1998)
The story that became "Little Green Men" was originally pitched for Star Trek: The Next Generation. In its original conception it would have the Enterprise in pursuit of four Ferengi who had traveled to the mid-1900s and crashed. Their bodies and ship were recovered by the United States military, leaving the Enterprise to clean up. The pitch was well-received by Rene Echevarria, but not used because he wanted just a single time travel story per season, and one was already in the works. Five months later, the story was successfully re-pitched for Deep Space Nine, using Quark. 
Sarek and Spock storyEdit
A story that D.C. Fontana and Herbert J. Wright pitched, during TNG's first season, would have featured Spock, Sarek, and Romulans. Fontana detailed the specifics of the proposed plot, which had some similarities to the ultimately-produced two-parter "Unification I" and "Unification II"; "We're taking on a mysterious Vulcan visitor who, of course, turns out to be Spock, and his mission is to rescue his father, who has been captured by the Romulans while on an exploratory peace mission. Now he's being held hostage, and they want Spock." Fontana was told that the plot was not granted production approval due to the unlikeliness of obtaining either Mark Lenard as Sarek or Leonard Nimoy as Spock. (Star Trek: The Magazine Volume 1, Issue 2, p. 87) According to Herb Wright, the reasoning was that Nimoy had "a falling out" with Gene Roddenberry and instead directed Three Men and a Baby. Wright noted of the story, "I thought [bringing Spock back] would have been great first season." (Cinefantastique, Vol. 23, No. 2/3, p. 48)
See Spot RunEdit
"See Spot Run" was written by Michael Halperin.
"Somewhen" was written by Vanna Bonta.
The USS Enterprise-D received a distress call from the transport ship Pleides which got caught in the Docleic Triangle, a space version of the Bermuda Triangle. The Enterprise followed the distress call and went into this area of space, filled by several energy rings. While passing each energy ring, a different time continuum was created. The changes during these leaps in time include a living Jack Crusher who served as first officer to a beard wearing Captain Jean-Luc Picard and a different Geordi La Forge, who can see, has a wife and three children, and never joined Starfleet.
Data is the only crewmember who realized all these changes and convinced Captain Picard that the Enterprise should leave this area of space because of a nearby ion storm. Aboard the Pleides no one answered the hails. While traveling back through the leaps of time, Doctor Beverly Crusher decided to stay in one of the created alternate timelines and following Wesley Crusher was never born. The Enterprise went back to the timeline and Captain Picard convinced Dr. Crusher to return with the crew. (Das Star Trek Universum, Band 2)
Two Yuffs Two ManyEdit
"Two Yuffs Two Many" was written by Richard Krzemien, draft date 9 July 1992. (The Making of the Next Generation From Script to Screen - Part Two)