forgivenunforgotten
If bones had voices, his would be singing. Or crumbling. Or something extreme because he's done it at last, he's caved and dropped a mission and killed people and run out on every organization that ever thought it could keep him. He texts Fury with shaking hands.
Sorry, it says, I can't do this anymore.
Not like he has a choice now. Three months undercover, three months away from any kind of comfort, any semblance of humanity in Hydra's hellhole because they managed to trust him. He conceded to do horrible things for their cause and he became part of the inner circle and found out how far their roots reached.
(Too far. Way too far.)
He tried to survive there. He tried to fit himself in and joke with people who genuinely thought they were doing this for the greater good and not throw up every day when he got back to base. He tried. He even tried to believe what they did to ease the agony of it all.
He failed.
And so he ripped apart what he could, shot officials, broke servers and sent information back to S.H.I.E.L.D. personnel that he trusted, and got the hell out.
(And where was there to go?)
It was too dangerous to go back to his friends. Hydra would be after him, after everyone he knew and loved. But there was one person who was used to dealing with them, with tearing them down at every turn. There was one person he trusted to survive. So bloody and beaten and broken, he showed up at Erik's door once again, and begged to come home.