Nonetheless, the plot was fairly interesting, as it was very loosely inspired by a historical event, the imperial succession controversy that clouded the ascension of the Ching emperor Yongzheng in the early 18th century.

In the movie version of the story, the 4th Prince (Yongzheng) seeks refuge in the Yun Fortress of a martial arts clan, after being pursued by the henchmen of his rival the 14th Prince. The leader of the fortress has been encouraged by a young swordsman, the fiancé of his daughter, to support the 4th Prince, but the old man is ambivalent. The young swordsman had a letter from his master explaining why they, as Han Chinese, should support a Manchu, but he loses ineptly loses the letter twice during sword fights.

All sorts of additional plot twists and machinations happen along the way until the master of Yun Fortress finally makes up his mind.

Ultimately, I would've liked the movie more if the fights were faster, better choreographed, and more varied. A number of fights seemed rather clumsy affairs where the opponents wildly swing and hack at each other.

After this experience and several others, I've become very wary now of any martial arts movie made in the late 1960s, as the action standard then really paled compared to the 1970s and early 1980s.