Five-year-old Mona knows something is very wrong, when her older brother Pancho doesn't come home one night. Her evil sister, Christi, is to blame because Pancho is always defending her. Mona only knows he is in trouble with the police. Now that Pancho is gone, Christi is brutal, constantly terrorizing Mona. One afternoon, her parents go on an overnight trip and leave her older sister in charge. Things take a turn for the worse as her sister's carelessness...