Star Trek: Deep Space Nine season 1 almost ended with an explosive crossover episode featuring the cast of Star Trek: The Next Generation. Premiering in 1993 in the middle TNG season 6, DS9 had considerable crossover with its parent show. It was Captain Jean-Luc Picard (Patrick Stewart) who briefed Commander Benjamin Sisko (Avery Brooks) on his mission to prepare Bajor for entry into the Federation in the pilot episode, "Emissary." The show also featured TNG's Miles O'Brien (Colm Meaney) as a main character, and Lieutenant Commander Worf (Michael Dorn) transferred from the USS Enterprise to Deep Space Nine in season 4's premiere, "The Way of the Warrior".
However, the original DS9 season 1 finale was set to guest star far more than one character and would have featured the whole crew of Captain Picard's TNG Enterprise. The proposed story focused on Picard and the TNG cast helping Sisko and his crew protect the station from being retaken by the Cardassians. Interestingly, this foreshadowed what would eventually form the climax of DS9 season 5, when Gul Dukat (Marc Alaimo), in league with the Dominion, retakes DS9 and other former Cardassian territories.
Why DS9’s Season 1 TNG Crossover Didn't Happen
Given that DS9's series premiere, "Emissary" started with the Enterprise-D docked at the station, it would have been a neat bookend to have it return for the finale. There's also the tantalizing possibility that aiding the DS9 crew in repelling a Cardassian invasion would have led to Sisko resolving his issues with Picard. It's also interesting to ponder how an attempted Cardassian invasion of DS9 in season 1 would have changed the whole narrative arc of the show, as the fragile relationship between the Federation and the Cardassian Union in the lead-up to the Dominion War was integral to DS9's early years.
Interviewed for the book Captains' Log Supplemental - The Unauthorized Guide to the New Voyages, showrunner Ira Steven Behr said that they didn't have the required budget to make such an epic finale work out. Interestingly, the bare bones of the story were used as a template for the season 2 finale, "The Jem'Hadar", which began DS9's Dominion War arc. It also featured the destruction of the USS Odyssey, a Galaxy Class starship that looked exactly like the TNG Enterprise. Without the budget for a TNG crossover and with the story idea vetoed by producer Rick Berman, an alternate story to link back to the events of "Emissary" was instead developed as the season 1 finale.
DS9's Season 1 Finale Broke A TNG Trend
DS9's actual season 1 finale, "In the Hands of the Prophets" bucked a trend established by TNG by not ending the series on a cliffhanger. Partly, this was due to the same budgetary concerns that nixed the TNG crossover, because cliffhanger endings require increased action sequences and more investment. Cliffhangers had become the norm in TNG season finales since the explosive cliffhanger of season 3's "The Best of Both Worlds", in which Acting Captain Will Riker (Jonathan Frakes) orders the Enterprise to fire on the Borg cube containing the assimilated Jean-Luc Picard.
Viewers of Star Trek: The Next Generation had to wait the whole summer to find out if Picard would survive, and whether the Federation could defeat the Borg Collective. However, Behr felt that as exciting as cliffhangers could be, they could also quickly become a gimmick. Instead, DS9 season 1 ended with a story about Bajoran fundamentalists that marked a significant development in the relationship between Sisko and his second-in-command Major Kira Nerys (Nana Visitor). It was this focus on character over spectacle that would eventually come to define Star Trek: Deep Space Nine.