Effects of Obliteration by @geneticallydead.ao3
Before the fall of the Soviet Union, the Winter Soldier was sent to the American arm of Hydra - only there was a malfunction in the cryo-unit that meant it couldn't be opened, and it was left, powered but abandoned, in an underground base. 25 years later, the Avengers find it. I enjoyed this AU of how Steve gets Bucky back.