Alita has no memory of her past but possesses an instinctive, lethal aptitude for the ancient martial art (“Armored Art”). As she pieces together her identity, she discovers she was a high-tech battle unit from Mars’s elite warrior class. She becomes entangled in a gladiator-like sport called Motorball (a deadly roller-derby mixed with NASCAR) and must face Vector (Mahershala Ali), the factory boss, and the monstrous cyborg Grewishka, all while trying to protect those she loves.