Lao Gou is a forest ranger stationed at Tianshan Mountain in Western China. He patrols the mountains accompanied by dogs which he trains and keeps in kennels, giving rise to friction between him and his wife Wang Rong who feels that Lao Gou takes better care of the dogs than he does his own wife and two daughters. One day Lao Gou crosses the path of Zhang Biao, a ranger who arranges an illegal hunting expedition which targets a rare local wolf under Lao Gou's protection. Lao Gou's actions lead to Zhang Biao's imprisonment, and while serving his sentence, Zhang Biao swears to take revenge against Lao Gou. When he is eventually released, Zhang Biao puts his plans into action and attacks Lao Gou, his dogs, and even his family. The strain of the ensuing troubles leads to the breakdown of Lao Gou's marriage. Ultimately his elder daughter's life is threatened as a result of Zhang Biao's growing passion for her. After various struggles, Lao Gou and his younger daughter find themselves stranded in the snow and attacked by the wolves. Rambo, Lao Gou's lead dog, runs to get help, but it is eventually Zhang Biao himself who saves the day by shooting the protected wolves before giving himself up to the police.