She died on a meaningless survey mission.
There's no other way for me to put it. I was heartbroken. I spent decades trying to get us home. At first, "us" meant a Starfleet crew, the crew I originally put together to track down a missing Maquis ship. I recruited Tom Paris personally, but Harry Kim's innocense was something I cherished from the first moment I met him. Few people know this, but I was involved in the program that saw the development of the Emergency Medical Hologram. I knew the Doctor before anyone else among my crew. It was part of my own development to learn to treat him as an individual. My dear friend Tuvok had gone undercover as a member of the Maquis crew. He was in fact the reason I chose the assignment.
When the Caretaker brought us to the Delta Quadrant, it quickly became apparent that the Maquis could no longer be considered an enemy, but rather allies, in a mutually beneficial pact that would help us to operate the one ship that would allow us to undertake our journey home. That was how I met B'Elanna Torres. And that was how I met Chakotay.
He had been the captain of the Maquis ship, and therefore had every reason to resent my decisions and lead a justifiable mutiny against my intentions and my assumption of command. Instead, he chose to put his personal feelings aside. He saw the wisdom of cooperation. He was the only one who truly understood what lay ahead. There were times I believed he understood it better than I did.
We took on a pair of passengers fairly quickly, natives of the Delta Quadrant, Kes and Neelix. In their own ways they proved valuable to our mission. The next passenger was Seven. She had been a member of the Borg Collective almost her whole life. A fluke severed her connection to the hive mind, and I made it a personal priority to oversee her rediscover her humanity.
I began to feel as if I were Seven's surrogate mother, nurturing her unsteady first steps back into an individual existence, one where she had to depend on her own instincts, trust others she couldn't immediately interpret, whose voices expressed opinions she herself couldn't immediately understand. For so long she had known only cool intellect, had mastered dozens of scientific principals, and knew her role beyond a shadow of a doubt. Her life had been intuitive.
And I marveled each day that she struggled to make progress, even when I was horrified by her actions, even when she took so many opportunities to betray my trust. Yet I never gave up. Like Harry Kim, I saw Seven to be an innocent, even if she found it difficult to define herself in such a vulnerable way. For every misstep, there was a moment when I could see past her veneer of defiance and see the vulnerable little girl whose life had been stolen from her, the woman who only wanted to crawl back into the protecting arms of her parents.
As the years advanced, she emerged more and more fully from the damaged drone into an individual who didn't need me anymore. She began to form her own relationships. She found romance, with Chakotay. A part of me looked on this with melancholy. I had dedicated so much of myself to the mission, to the singular goal of getting us all home, I had lost the very thing I helped give Seven.
Then one day she died. I couldn't process it then. I mourned for a few hours, spent perhaps more time than usual in my quarters. I was always prone to brooding. To some, it probably seemed natural behavior on my part. I was so lost in myself, I failed to realize the impact her death had on Chakotay.
If I displayed my customary reserve for such an occasion, Chakotay became a completely different person. Over the years, he had become a little more withdrawn, the longer our journey took and the less he was needed to mediate between Starfleet and former Maquis crewmembers. But suddenly he was cold even to his closest friends, even B'Elanna. We barely spoke. In hindsight I wonder if he blamed me, if he had finally gotten around to it.
We all grew older. Decades passed. He aged worst of all. He died on heart failure on the exact anniversary of Seven's death.
I suppose that's when I first started making my plans. Even after we completed our voyage, returned to the Alpha Quadrant, I wasn't satisfied. Because of Seven. Because of Chakotay. There were other reasons, but I won't try and kid myself.
I knew that I would have to go back in time and get us home sooner. This was to be my endgame.