On an ordinary street in the American Midwest in 1958, Captain America suddenly crashes through a high window, bounces off of an awning, and flees the gunmen pursuing him. He seizes a gun from a newsstand owner who is in league with the baddies and shoots loose a high-tension wire. He then hurls his shield through the windshield of an approaching car full of enemies and when they pile out into the wet street, Cap calmly tosses the electrical cable at them. When he turns Cap is confronted by red-haired woman dressed in widow’s weeds, holding a pistol and a grenade…. The instructor calls off the exercise and we discover that we are in the Soviet Union, in a mockup of America designed to train KGB agents, and that "Cap" was the living weapon known as the Winter Soldier. He gives us a recap himself: Bucky Barnes, Captain America’s wartime sidekick, thrown into the English Channel when Baron Zemo’s drone-plane exploded. He was recovered by the Russians, who gave him a bionic arm and brainwashed him into serving as their special assassin. He begins a clandestine affair with Natalia Romanova, the Black Widow, and everything seems well…
The Winter Soldier is dispatched to West Berlin to assassinate Sergei Ivanovich, a former KGB official who is defecting to the west. He gets a bead on the man with a sniper rifle but is distracted when Ivanovich’s young daughter suddenly runs up to him. His aim is thrown off, and the bullet strikes Ivanovich in the shoulder. The Soldier flees only to encounter the Black Widow in an alley. Together they pursue the quarry, with Bucky shooting down bodyguards and CIA agents until the father and daughter are cornered in an alley. While Natasha holds the child safely at a distance, the merciless assassin kills his target with a dagger.
Reporting to his superiors the next day, he is irritated that he was not told his victim would have his child present. The officials realize his conditioning is wearing off and he is starting to recover his old morals and is even speaking English. So the decision is made to keep him in suspended animation and only let out when he is needed to kill. Eventually Captain America would restore his mind and memories with the Cosmic Cube and with the love of Natasha (whose aging is retarded through Russian biotechnology) he manages to return to a semblance of normality….
And now Bucky is visiting his sister Becca in a nursing home, to introduce her to Natasha. As they leave Bucky reveals that he needed to tell his life story to Becca, even though, suffering as she is from Alzheimer’s Disease, she will not remember any of it. And so the two head out on Bucky’s new mission to right the wrongs he committed as the Winter Soldier.