Set in 19th Century Canada, Brigette and her sister Ginger take refuge in a Traders" Fort which later becomes under siege by some savage werewolves. And an enigmatic Indian hunter decides to help the girls, but one of the girls has been bitten by a werewolf. Brigitte and Ginger may have no one to turn to but themselves.
　　15岁的布里吉特与16岁的珍姐是感情要好的亲姊妹，一晚珍姐首次月经来潮，二人跑到街上“庆祝”一番，回家途中珍姐受一群半人半兽袭击，身体被抓伤，回家后发现伤口痊愈甚速，更可怕的是有毛发长出，尾骨长出尾巴。珍姐慢慢变成人狼，性情大变，开始嗜血且放荡不羁。布里吉特找来对化学疗效植物学家森帮手，但珍姐对妹妹的疑心越来越严重，兽性盖过人性，并且开始肆杀无忌……