The woman in question is Zoey, a skilled fighter who has studied martial arts since she was a child. After her father's murder, she throws herself into training and fighting in underground MMA bouts. Along the way, she allies herself with a tough-talking trainer named Duke and a police detective named Monroe, who is sympathetic to her cause.
As Zoey gains notoriety in the fighting world, she begins to attract the attention of the Russian mobsters responsible for her father's death. They attempt to intimidate her, but Zoey is relentless in her pursuit of justice. Along the way, she also learns to confront her own inner demons and reconcile with her strained relationship with her mother.
Ultimately, Zoey faces off against the mob boss in a climactic fight that tests her skills and her resolve. In the end, she emerges victorious and is able to bring closure to her father's death. The movie is a thrilling action-packed ride, as Zoey battles her way through the seedy world of the underground fight scene in pursuit of her vengeance.