A teenage girl, orphaned at a young age, is raised and trained by a secret government program to become an elite international assassin. Despite excelling in her deadly skills under the strict guidance of her handler, she yearns for the normal experiences of adolescence she reads about in teen magazines. Faking her own death during a mission, she seizes the opportunity to reinvent herself and enrolls in high school as a foreign exchange student named Megan. As Megan, she tries to navigate the complexities of teenage life, struggling with new social dynamics, forming friendships, and experiencing her first crush.

However, her past catches up with her as former allies and enemies alike discover her new identity. Balancing high school life with evading capture, she must use her training to protect herself and those dear to her from the looming threats. As challenges mount and her old and new worlds collide, she is forced to confront what kind of life she truly wants and what she is willing to do to protect it. The climax brings her to a point where she must reconcile her desire for normalcy with her intrinsic skills and responsibilities as a trained operative.