After Thanos was defeated, Steve returned the stones and came back with a revived Natasha whose first order of business in her resurrection was finding her sister Yelena. Too bad she didn't know to look for her other sister, a sister they both thought they'd lost years ago. Anastasiya grew up in the Red Room with Natasha and Yelena, but when a rough training session unlocked her special powers, she was taken away and separated from the only family she'd ever known. She was trained in secret to be as assassin, to be the best assassin moving always in shadows. Until she escaped her handlers. Now she works as a mercenary, still solely in the shadows. What happens when Anastasiya comes across long lost sisters she was made to believe betrayed her? What happens when Yelena and Natasha see a ghost from the past? And what happens when a super soldier gets caught in the middle falling for the secretive and damaged girl? Well, Tony throws a party of course.