Irene spent eighteen quiet years scrubbing gymnasium floors and cleaning locker rooms, keeping a solemn vow made to her late husband to abandon violence forever. Her rebellious teenage daughter idolizes mythical fighters seen in tournament reels, openly resenting Irene for what appears to be spineless timidity.
The fragile peace shatters on the girl's eighteenth birthday when a ruthless crime syndicate targets her to settle an ancient score. Breaking her long-standing oath without hesitation, Irene unbinds her lethal martial arts mastery, taking on an entire army of hitmen to prove that a mother's protection is absolute.
