For this prompt thing.
Star Trek: Deep Space Nine
AU where Julian’s genius and ability are not due to genetic resequencing, but hard work and effort, as well as genetic luck.
Julian Bashir/Elim Garak, perhaps. Certainly if I actually write this, it will be.
It is enough to lose him his Starfleet commission and his medical license that Julian is accused of being genetically modified. A whisper of the wrong sort to the wrong person, and his father has cost him everything he has worked so hard for, because no matter how much his friends are willing to fight for him, there is too much fear higher up in Starfleet for the taint to be cleared once offered.
Julian is offered a chance to get a Bajoran medical license, but he would still not be allowed to work in the infirmary on the station because of Starfleet regulations, and the fear of those higher up the chain of command. He can have his career or his friends and found family. Neither is quite enough, and after a few months of trying to find a way around the obstacles Starfleet has thrown in his way, Julian leaves on the eve of war.
No one on the station sees him again for several years, while the Dominion ravages the Alpha Quadrant. Only letters, exchanged through several intermediaries, reassure the crew he is alive and thriving. Text, never images.
Alongside these, there are coded communications being regularly delivered to Bajor from behind enemy lines, useful information about the Dominion’s war efforts. Precious information that only Garak and Sisko people know the source of, and neither is willing to talk about it.
A few weeks after the first offensive strike of the Federation into Cardassian territory, the letters stop, though not the coded communications. Garak and Sisko do not tell the others that Julian is still alive, even to the point of having a memorial service for him.
Only after the war ends does anyone see him again, and it takes Garak most of a year to track down where Julian is at, around all the other various things he has to do on Cardassia. Julian could have come to him, sooner, but that would imply he wants to return to the frustration of a life where he can have career or family, and he has no intention of doing that, when he could have both. Even if it’s not the family he’d built before.
“I have to say, gray suits you very well, Doctor.”
“And being home suits you, Garak.”