Mary is a hitwoman for an organized crime family in Boston. She leads a solitary and dangerous life, executing jobs with precision. During a hit, she discovers that her actions have orphaned a young boy named Danny. Guilt-ridden, Mary tracks Danny and finds him in dire conditions, struggling to survive. Feeling a sense of responsibility, Mary takes Danny under her wing and tries to provide him with some stability, despite the violent world she operates in.

As she attempts to shield Danny from her criminal ties, Mary's actions begin to draw attention. Her decision to protect the boy threatens her standing within the crime organization, leading to escalating tension and conflict. Meanwhile, forces within the criminal underworld become increasingly hostile, putting both Mary’s and Danny's lives at risk. Facing dangerous adversaries from all directions, Mary must navigate her way through treacherous encounters, fighting to keep Danny safe while confronting her past misdeeds.