The landmark alternate timeline episode from the middle of Star Trek: The Next Generation's third season, "Yesterday's Enterprise," turned 30 this week — and remains one of the most beloved and acclaimed episodes of not just TNG's run, but all of Star Trek. The episode routinely pops up on "Best Of" lists for its series and for the franchise as a whole, and it's the kind of episode so full of juicy plot and entertainment value that you can show it to newcomers in an effort to convert them to the wonders of The Next Generation. It's also one of the darker episodes in The Next Generation's seven-season run, but according to two of the episode's writers, it was almost much darker.
As you may recall, "Yesterday's Enterprise" features the crew of the Enterprise-D encountering the past incarnation of their beloved starship, the Enterprise-C, as it enters the present of the show from a rift connecting to the past. By escaping its own past and accidentally traveling to the future, the Enterprise-C dramatically changes the timeline of the series, creating an ongoing war between the Federation and the Klingons that the Federation is on the losing end of. The Enterprise-D is turned into a warship, Worf and Troi are no longer part of the crew, and Tasha Yar is returned from the dead to serve on the bridge, but only the Enterprise's engimatic bartender Guinan notices that something is wrong. It's up to her to convince Captain Picard that the timeline has been altered in a very bad way, and the only way to save it is to send the Enterprise-C back to the past on what amounts to a suicide mission.
This moral and tactical quandary culminates in the Enterprise-C crew agreeing to go back through the rift while the Enterprise-D defends them from attacking Klingon ships. Outnumbered and outgunned, the Next Generation crew are fully prepared to go down with their ship to save millions of lives by changing the timeline, and Commander Riker actually does die onscreen in a rather brutal way. It's a dark climax in a dark episode that's leavened by the resetting of the timeline for a largely happy ending, but it could have been a lot worse.
In an oral history from The Hollywood Reporter to celebrate the episode's 30th anniversary, "Yesterday's Enterprise" co-writers Ira Steven Behr and Ronald D. Moore discuss everything from the rush to complete the episode (they were part of a team of four writers working on the draft) in time for it to air during sweeps to the way then-showrunner Michael Piller swooped in to write Guinan's dialogue. They also discuss their original ending for the episode, which would have included just about every member of the Enterprise-D bridge crew dying brutally in the standoff with the Klingons.
Though Behr recalled that the show did shoot death scenes for characters like Data and Wesley Crusher, the massacre was cut short by executive producer Rick Berman, who thought it would be "too violent" and "too depressing for the fans," even though the characters all ultimately survived.
"My memory is that Rick Berman pushed back on that and didn't want to see everyone on the bridge die," Moore said. "So I pulled back on what my original intention was, but [writing it] was a ball."
While discussing the ingenious alternate timeline worldbuilding of the episode, Moore also offered another amusing observation: He almost wishes the episode hadn't happened, so he could have used the same concept for Star Trek Generations four years later.
"If we hadn't have done that episode, then [the movie] would have been the Enterprise-A coming through that wormhole, and you'd have Spock and Kirk and everyone on that ship, we'd play the same story," Moore said. "They — the original crew — they had to go back to their deaths. And Guinan knew Kirk, and Guinan knew Picard, and that would have been an amazing movie."
Thank goodness Star Trek fans like to consider alternate timelines, because that means at least we can dream that version of the movie exists somewhere.