The Mission (Natasha x Bucky)

Once on the run, Natasha finds out she has a secret daughter, who still lives in the Red Room. At first, she doesn't believe it, because she would have remembered if she had a daughter, right? But then her sister Yelena gets into contact with her and she finds an old picture of her daughter. After finding out she has a daughter, Natasha and Yelena set out to find her.