After Steve Rogers died, his best friend and one-time sidekick Bucky Barnes stepped up to replace him as Captain America. This marked a dramatic change for him, as he had been brainwashed by the Soviets and turned into an assassin called the Winter Soldier. His path toward redemption was not easy, and he never felt worthy of being Captain America.
Eventually, Bucky's past caught up with him. Russian courts convicted him for crimes he committed as the Winter Soldier and the US government extradited him. He was locked in a gulag, an ordeal he was never meant to survive, and one that left him forever changed.
This transpired in Captain America #616-619, by Ed Brubaker, Mike Deodato, Chris Samnee, Butch Guice, Stegano Guadiano and Mitch Breitweiser. In this story, Bucky was forced to face his past, marking the culmination of events that began at the start of Brubaker's run.
Bucky was tried in absentia by the Russian government for murdering Russian civilians while he was the Winter Soldier. Despite having no memory of these killings, Bucky admitted that it was possible he committed them and imprisoned him in an old Soviet gulag. The resurrected Steve Rogers vows to help get him transferred to US custody. The warden explains that if Bucky tries to escape before his transfer is approved, he will become a fugitive of both Russia and the US government. As such, Bucky has to wait indefinitely, trying to survive until bureaucrats in Washington and Moscow approve his transfer. During this time, Black Widow and Sharon Carter investigate the matter and discover a conspiracy at work to frame their friend.
Bucky is accosted by Yuri Petrovich, who used to be the mech-suited Soviet soldier known as the Crimson Dynamo. Petrovich was convicted of turning on his superiors, and Bucky apprehended him when he tried to flee justice. Now, Petrovich runs the gulag from the inside. Bucky is assaulted by Petrovich's men in the mess hall, and even though he does not defend himself, the warden threatens to lock him in solitary confinement for fighting. However, the real fighting begins when the guards drag Bucky from his cell in the middle of the night on Petrovich's orders and force Bucky to fight in a gladiatorial match against another Russian super-soldier, the werebear known as Ursa Major.
In the following days, Bucky is subjected to hard labor and further gladiatorial fights as different prison gangs, guards, and old Soviet government agents-turned-inmates all assail him. The gulag and all of its inhabitants are legacies of the violence and corruption leftover from Soviet Union's past. Eventually, Bucky realizes the warden is actually one of his old handlers who brainwashed him as part of the Winter Soldier program. The warden and others have not been trying to kill Bucky, but rather to psychologically break him so they can access codes stored in his memory. These codes are the only way to activate sleeper agents in the US from a program known as Project Zephyr. Desperate to stop the threat posed by these sleeper agents, Bucky breaks out of the prison, more concerned about saving lives than whether or not he is a fugitive from the law.
Bucky can never be a symbol of hope like Steve, but that does not mean he is beyond redemption. The convicts and guards in the gulag perpetuated the crimes of the Soviet past so that there was little distinction between prisoners and prison staff in one of the first Marvel stories that seriously interrogates the Soviet Union's legacy in modern Russia. Bucky was also a part of that world, and he's just as much a relic of it as anyone or anything else. The Winter Soldier cannot escape his history, but he will not let it keep him from being better, as this story and others like it prove.