As we've already explored with Star Trek: The Next Generation, what goes on behind the camera in Gene Roddenberry's iconic franchise is often just as fantastical as what's being filmed in front of it.
Of course, every television series has its behind-the-scenes stories to tell but, with over 800 episodes now in the books, Star Trek has some 6 decades of anecdotal misadventure to pull from. Add to this the combination of worldwide fan-investment clashing with constant network apathy, and you've got the perfect mix for a show that feels very important now, but was held together with tape at the time.
While this is particularly true of the Original Series, The Next Generation, and Voyager, Deep Space Nine was about as haphazard and directionless a property in its early days as it's possible to find. Not unlike the titular station on which it was set, production was a mess of in-fighting, conflicting ideas, and lofty ambitions, and the only thing all parties were in agreement on was that it was a) Star Trek, but b) there would be no actual trekking.
Thus the end result is an initially messy arrangement of characters and ideas, but one that would emerge as arguably the franchise's greatest series once everything found its rhythm. But, as ever, it's the getting to that point that makes for the best stories, and DS9 had plenty of those.
10. Ro Laren
We start with perhaps the most famous story from Deep Space Nine's pre-production, and a genuine sliding doors moment in the history of the entire franchise. Major Kira Nerys, both a pillar of this show and arguably one of the greatest female portrayals in all of Star Trek, was never supposed to be a part of the story. In fact, she was thrown in as a last-minute addition when the character Paramount originally envisaged fell apart.
That character? The Next Generation's Ro Laren.
The initial treatments for Deep Space Nine had Michelle Forbes' recurring Bajoran tearaway as one of the major focal points of the show. Early versions of the writer's bible had her acting as both the Federation liaison with the Bajoran Militia, serving as Sisko's First Officer, becoming good friends with (the initially quite uptight) Dax, and having an adversarial relationship with Quark. Sound familiar?
However Forbes really wasn't interested in a full-time run on the show and, after several rewrites were attempted to accommodate her only being used occasionally, a late decision was taken to just write an entirely new Bajoran character; Major Kira Nerys.
It's near impossible to imagine Deep Space Nine without either Kira or Nana Visitor, but that's very nearly what we got.