The former CIA agent, Mark (played by Jim Kelly), arrives in Hong Kong and starts investigating the diamond theft. He meets a local taxi driver and martial arts expert named Li Chen (played by Sing Chen) who agrees to help him. They soon discover that the theft was orchestrated by a ruthless crime boss named Mr. Chin (played by Wong Chung), who wants to use the diamond as leverage in a business deal.
Meanwhile, one of the thieves, Tony (played by Bolo Yeung), is having second thoughts about his criminal lifestyle. His girlfriend, Lily (played by Doris Lung), wants him to leave the organization and start a new life with her. Tony is torn between his loyalty to Mr. Chin and his love for Lily.
As Mark and Li Chen close in on the diamond, they are ambushed by Mr. Chin's henchmen and engage in an intense martial arts battle. Tony and Lily also get caught in the crossfire and must fight for their lives.
In the end, Mark and Li Chen retrieve the diamond and deliver it to the insurance company. Tony decides to leave the criminal organization and start a new life with Lily. Mr. Chin is arrested and brought to justice, thanks to Mark and Li Chen's efforts.
The Tattoo Connection is a classic martial arts movie from the 1970s, featuring impressive fight scenes and a compelling storyline. It is a must-see for fans of the genre.