This has been driving me nuts. For most of Star Trekās history, the Prime timeline holds together no matter what happens to it. Kirk jumps around, Picard gets stuck in time loops, Janeway rewrites entire centuries, and the universe just snaps back like it never happened. Time feels elastic but stable.
Then Nero falls through a black hole, and everything falls apart. The Kelvin event doesnāt just make a new branch going forward. The ripple hits both directions. It rewrites history that should already be set. Starfleet looks different. Vulcan feels different. Even the technology and design philosophy seem changed long before Nero was ever born. That sounds less like a branch and more like time itself got rewritten.
Once that happens, the Temporal Prime Directive starts to fall apart. It only works if time moves in one direction. You can āfixā something when thereās a clear before and after. But if the ripple goes both ways, there is no original timeline to go back to. The moment the Kelvin universe forms, the concept of Prime reality stops being a single point.
And thatās before you even touch the Mirror Universe, which is not a branch at all. It has been running beside the Prime since the beginning. So now we have at least three full continuums: Prime, Mirror, and Kelvin. But thatās not the end of it. The Star Trek Online timeline exists as an extension of Prime, playing out events after Nemesis and even connecting to the Temporal Cold War. The licensed novels follow yet another line, continuing after Destiny and Coda, where the multiverse literally starts to collapse under the weight of too many versions.
So what is the Federation even supposed to do with the Temporal Prime Directive at this point? Which universe counts as the real one? Do you merge them? Do you pick one and call it Prime? Or do you admit that every version is its own living reality with its own moral weight?
Maybe the point isnāt fixing anything anymore. Maybe the Temporal Prime Directive is just damage control. Once time starts rewriting itself both ways and spawning whole new continuums like STO or the book universe, thereās no putting it back together. The best you can do is keep the pieces from smashing into each other and hope reality doesnāt collapse under the strain.


I think that is what bothers me most about the Kelvin timeline is it seems not to conform to the Prime. The only way I can square it is that the trip through the blackhole not only went back in time but to a different reality.
It bugs me a bit too, but I guess thereās nothing really wrong with it being āthe exception that proves the ruleā - something extraordinary happened in that case, unlikely to repeat.
And the pre-existing time travel rules werenāt exactly clear-cut, either - my original response glossed over bootstrap paradoxes like āTimeās Arrowā, where the characters travel back in time because they found Dataās head in San Francisco, which was only there due to said time travel.
But then, from the perspective of people in the future, I suppose all time travel events look like bootstrap paradoxesā¦