Abagail Petrova has been stuck in the Red Room since she was 13 years old. There she met Natasha Romanoff, who trained her and befriended her. They became close bonding over shared trauma. Except one day, Natasha gets out, leaving Abagail alone in the Red Room. Soon after Natasha comes back with her team to break Abagail out so that she can become the next avenger. Abagail works to try to get back to the life she once had before her parents were killed, making friends and forming relationships, and don't forget to mention training with the avengers to possibly save the world. With Bucky trying to help her return to normal, will they form a special bond or will her abilities to socialize be forever damaged?

What if a girl fell from the train with bucky that day? What if she was steve's sister? What if she was also taken by hydra? The girl that fell was Bella Roger's The girl that survived is The Nightshade.