Diana (Michelle Rodriguez), a young troubled girl who doesn't know how to control her anger, discovers one day the secret world of boxing. She knows she has finally found a place where she truly belongs. She begins training and soon she competes and gains momentum as a true contender. As Diana builds physical strength, she becomes more self-assured and ultimately, confident enough to allow herself to become vulnerable - a burden that weighs heavily on her as she prepares for the most important fight of her life.