The Avengers thought they knew everything about the Winter Soldier. They were wrong. Y/N Rogers is Steve Rogers’ younger sister—and one of HYDRA’s most dangerous secrets. Alongside Bucky Barnes, she was taken, conditioned, and transformed into one of HYDRA’s most lethal assets. While Bucky became the Winter Soldier, Y/N became known as the Black Widow of HYDRA, feared for her precision, loyalty, and ability to survive anything they put her through. But there was one thing HYDRA could never completely erase: Y/N and Bucky’s love for each other. For years, the two secretly clung to one another through missions, torture, and endless conditioning. They became HYDRA’s favorite weapons—and each other’s only source of comfort. Then Steve Rogers discovers the truth. His little sister is alive. And she’s standing beside the Winter Soldier. When the events of Civil War begin and Bucky is blamed for the bombing, Steve refuses to believe his best friend is responsible. But when Y/N appears beside Bucky, the Avengers are forced to confront an even bigger problem: two enhanced HYDRA assassins who will do anything to protect each other. Tony sees them as dangerous weapons. Steve sees Y/N as the sister he thought he lost. Bucky sees Y/N as the only person who remembers who he was before HYDRA. And Y/N is caught between the brother she desperately wants to come home to and the man she has loved through every nightmare. The Avengers wanted the Winter Soldier. HYDRA gave them two. Now Steve has to choose between saving his sister and saving the man she refuses to leave behind.