A grieving husband tries to uncover the truth behind his wife's suicide, leading him to discover a tragic tale of infidelity and redemption.

This mid-1970s martial arts classic stars Sonny Chiba as Mu Yun Tek, a young man trained in the Thai fighting style since childhood to one day avenge his parents' death. When a fellow student kills their teacher, Mu Yun's thirst for vengeance grows. The brutal action never stops as Mu Yun teams up with an Interpol agent (Tadashi Yamashita) to find the culprit, who insists that their former master was a drug dealer who had to be destroyed.

Unicorn travels to a village troubled by gangsters in search of revenge for the murder of his parents years before. The task is made more complicated when he befriends a middle-aged woman and her son who begin to admire and depend on him.