When all but two of the men in the Yang family are massacred, the result of a plot orchestrated by Sung Dynasty general Pan Mei (Ku Ming) and his Mongol allies, only son No. 6 (Alexander Fu Sheng) is able to return home to impart the grim news. Unfortunately, he has been driven insane by the horror, while son No. 5 (Gordon Lau Kar-leung) has become separated from his brother and is wandering the countryside. Narrowly escaping death at the hands of Pan's troops, No. 5 decides to bide his time by becoming a monk at Ching Lang Temple. However, his rage and thirst for vengeance is a violation of fundamental Buddhist teachings, causing the monks (led by Phillip Ko Fei, in a career highlight for the actor) to reject him. Undeterred, No. 5 proceeds to shave his head anyway and, refusing to leave, causes the monks much grief. Meanwhile, word has come back to Lady Yang (Lily Li Li-li) that her fifth son still lives, so she orders her eldest daughter, No. 8 (Kara Hui Ying-hung), to disguise herself as a man and bring him back home. Pan's spies are everywhere, however, and she is soon captured, forcing No. 5 to come out of hiding and attempt a rescue.

A superb period thriller, THE EIGHT DIAGRAM POLE FIGHTER is exceptional in every department, combining a traditional but exciting storyline (which provides ample opportunity for tragedy and high emotion) with outstanding martial arts (the stick fighting battle between Gordon Lau and Phillip Ko is the standout among several highlights). Originally the film’s star, Alexander Fu died in a car accident mid-shoot, prompting a re-write that transformed Gordon Lau's character into the protagonist. This tragedy may partially account for the downbeat tone of the film, which is resolutely serious from beginning to end and ranks among the very best of director Lau Kar-leung's productions for Shaw Brothers. The exceptional supporting cast includes the director (in a small but memorable role), Johnny Wang Lung-wei, Chu Tieh-hu, Yeung Ching-ching, Wong Yue, Mai Te-lo, Lau Kar-wing, Hsiao Hou, Chang Chan-peng, and Yuen Tak. The Chinese title is the name of the staff technique that Yeung Ng-long (or Yang Wulang in Mandarin) developed from the Yeung Family Spear Technique. In real life, there are two stories as to why Yeung/Yang became a monk. One has him becoming disgruntled with fighting wars and entering Shaolin Temple to escape the carnage. The other has him being captured and offered a chance to join up with the enemy. He refuses, stating that he would rather become a monk than join with his rivals, a pledge that the enemy general makes him keep.