I first watched this movie in 2013 and made notes like "I have no idea what is going on." I watched it again in 2015 because it is a good movie with plenty of fights but I still missed the plot and details. For my third watch I finally get it but for brevity I'll just summarize. An official is suspected of supporting the Mongols so four special agents are sent undercover to investigate. They are two men and two women and after appearing in the opening scene when they appear again they have taken on different identities and roles. This is the first place for the viewer to get confused. Plus another hero played by Chuen Yuen enters the story and his true motives are hidden until the end.Lee Wan Chung played one of the special agents. When I started watching these movies I had trouble telling the actors apart. I focused on physical features or quirks to differentiate them. Lee Wan Chung. for me, was "Mr. Smiley". This guy had the greatest smile in Asian movie history. This movie he gets to do a lot of smiling and I loved it!This movie has 28 minutes of fight time which was probably the world record in 1972. The fights are mostly brief but frequent. All the action looks good and is not repetitive. The rest of the movie features such as costumes, set, color and such are all top notch as expected in Shaw Brothers movies of the era.I rate it as above average and recommend it for all fans of the genre. You can certainly enjoy it without getting all the plot and story details so just play it and enjoy the show.