I'm Seeing Red

Jim Kirk and Clara Oswald

Clara Oswald had the ability to travel through time. She jumps into a time rift and witnesses the death of the entire crew of the USS Enterprise which causes a catastrophe and the future to be riddled with only death and destruction.
Clara opens another time rift sending her 10 years before the death of the USS Enterprise where she joins Starfleet in order to become a crewman of the USS Enterprise and create an alternate reality where the world isn't ruled under a mad mans thumb. Along the way Clara becomes closer to James Tiberius Kirk than she every thought she would.