A Medea-like myth has haunted the Americas for more than 500 years, with currently more than 28 million believers in the United States alone. Over the course of one ominous day, this anguished spirit terrorizes New York City. As La Llorona escalates her appetite for vengeance, a young mother comes under her spell and collides with two detectives, a witch/curandera--and the lives La Llorona cut short.