I'd like to see a fully recovered, happy Bucky recaptured by Hydra and punished or beginning to be re-broken. Hydra gets the Asset back and treat him with as much dehumanization as they did before, except that this time it's both surreal for Bucky because he's solid in his understanding of himself as a person and how they broke him the first time around, and horrifying because he knows exactly how and why they're doing what they're doing but there's no getting out of it. Bucky knows he's a person, he's been treated as a person by everyone else for months or years, and yet here he is again with no control over his body, his food, anything, being talked about like an object (not even talked TO) and beaten, drugged and raped into compliance while slowly going crazy wondering if he ever got away at all.

+Rumlow and Rollins talking about Bucky like he isn't even there, about how funny it was that Steve or the avengers had the Asset pretending to be a person
++ Bucky slipping back into his old compliance when they order him around or rape him even though he's still very much still his recovered self, because it's less bad than if they have to beat him into compliance but he hates himself for it
+++ Bucky being painfully aware of how humiliating things like being hosed down or given an enema before cryo are, even though he remembers going through those things, he didn't experience any emotion about them the first time around and so didn't have to deal with the first hand emotional experience of it when he started recovering
++++ Bucky gets rescued, but Steve/Sam/Nat interpret everything he does as him being re-broken or reprogrammed even though he wasn't, and Bucky starts to doubt whether Hydra really broke him or not

(and yes, I've read Reunion Tour and the other one whose name I'm forgetting where Bucky gets blackmailed into going along with a Hydra gangbang, but if there are other fics in a similar vein I'd love links)