Tao Chen

The complicated story involves the military conquest of a peaceful island-nation by an evil despot and his sorcerer ally. His victory leaves the island's three heroic protectors dead, but, their young children are hidden away to grow to adulthood with different identities, unaware of their heritage, in hope that, in time, they might challenge and defeat the evil ruler. The charming Polly Kuan stars as one of these children who has been adopted by the conquerer himself, initially as an insult to the defeated hero, later as his protégé.

One criminal gang gets its hands on a stolen 'national treasure', and another gang steals it from then...One gang needs a martial arts expert to get the titular valuable back for them, but he won't do it so they kidnap his brother to coerce him to help.