Demon hunter Chen Xuanzhang (Wen Zhang) believes that he can purify any demon through love. However, his belief is shaken when his attempt to defeat a demon fish ends in a family's death and a victory for violent demon hunter Duan (Shu Qi). After getting encouragement from his master, Xuanzhang soldiers on to hunting down a demonic hog with the help of Duan, who has fallen in love with Xuanzhang. Despite help from other demon hunters, the hog gets away. As a last resort, Xuanzhang and Duan turn to the help of Sun Wukong (Huang Bo), who has been imprisoned for five centuries for his crimes in heaven.