Story line where Wash and Tucker are both mentally ill but really love and stay with eachother. And not mentally ill in a sort of, doesn't affect anyone way.
But like a severely, and harmful, kind. That they consistently have to push through and heal from. Like Tucker experiences actual Grandiase delusions, PTSD, goes through stages of brief psychosis. Cheats on Wash during a mental break, but doesn't even like it, ACTUALLY doesn't know why he did it. They have to talk about Tucker's sexual trauma, get to the root of the issue, while FIGHTING, and Wash is rude and angry and betrayed. They're both so miserable, and love eachother enough to not leave. Wash almost cheats on him back, just to get back at him, and hangs it over his head.
Wash, who experiences memory loss, PTSD, chronic illness. Who needs constant medical care, who’s pain is so severe that they're never even intimate. Who turns to violence when he's too out of it, who never means to, his pain and cognitive confusion put him back to his time as a soldier. Who still doesn't talk about his past more than he has too, Tucker who doesn't know his partner because his partner hardly knows himself anymore.
And they're still there rooting for eachother and healing eachother, they're the only reason the other is alive, when they are happy together their happier than anyone else, and when they're having issues it's always more severe than any other couple they meet.