As an expert of the 'Cross fists' technique, a reclusive kung fu master Li Pai perfects a lethal maneuver called the 'Shaolin Handlock' while an old wolf-in-sheep's-clothing friend Fang Yun-piao pays the unwitting Li a visit. Fang flees the country after duping and killing Li with a fatal counter-measure. Vowing revenge, surviving son Li Cheng-ying and sister Li Meng-ping follow Fang's trail to Thailand. Upon killing Fang, they discover that he was acting on orders of a local expatriate criminal kingpin, Ling Hao, who partnered with their father in black-market smuggling during the war. Proving his own worthy kung fu skills, Cheng-ying infiltrates Ling's organization as a hired hand to gain Ling's confidence to get closer to him much to the chagrin and suspicions of Ling's right hand man Kun Shih who engages Cheng-ying into a deadly cat-and-mouse game behind enemy lines. After a failed assassination attempt on Ling by Meng-ping, the intrigue is diverted to a beautiful kept blind woman on Ling's compound who provides a link to some deep-rooted family grievances involving everyone's shared past but not without consequences. Armed with the deadly Handlock maneuver, Cheng-ying and Kun Shih joins forces to exact revenge on the evil Ling Hao after the truth is unraveled.