The venerated Sun Chung made many different kinds of films for Shaw Brothers, including popular and renowned satirical comedies, contemporary action dramas, and magnificent martial arts movies. This is one of his last of the latter for the studio, so he wanted to have fun and let the audience share it. Toward that end he cast international favorite Alexander Fu Sheng as the title character who keeps testing the patience (and kung-fu skills) of his father, a small town bonesetter and herbal healer played by award-winning character actor Ku Feng. But when a local dignitary not only smuggles drugs but plans to give a Chinese treasure away to evil outsiders, the father and son unite to take on foreign fighters and even Japanese ninja's in a non-stop display of comic action prowess.