au where the taumoeba doesn't permeate xenonite, so grace never has to turn back for rocky.
he takes his four years completely alone, with coma slurry and taumoeba, steadily going mad as he loses all sense of self
he's fully nonverbal by the time he arrives on earth, overwhelmed by human presence, the space to move, the noise and color
he's mostly shielded from it -- they hospitalize him immediately, of course; he's emaciated and has scurvy, etc. Only he has a violent aversion to someone coming at him with a needle. terror, yes -- but cornered in a hospital room, there's nowhere to run. and he's not the same man that tried to run before. no, he grabs the closest thing to a weapon and tries to fight his way out. he is NOT letting them catch him again. he'd rather die!
he swipes some sweats on his way out and just. slips into anonymity. the savior of the world, the miraculous survivor of a suicide mission, and he didn't even stay long enough to be thanked, to be taken care of, to be healed
and once he gets out there, he realizes he doesn't even know what to do next except get away. he has no idea how to interact with society, how to ask for help or whether he can trust anyone. there's something cold living in the place his heart used to be. the part of him that always reached out for connection withered and died in those years of isolation with nothing but his memories for company. he doesn't feel human anymore. he feels like an alien that has landed on earth, some wild animal scurrying along the fringes
b plot of the world's top scientists trying to locate him and they keep trying to be very respectful and peaceful and everything and he reacts at a 12 every single time anyway, because it always brings him back to the day they sentenced him to death
only nobody seems to know that happened but him. everyone involved is either old, dead, or in prison.
c plot re: the taumoeba destroying the astrophage and the effects this has on the world
