The undercover agent with dragon tattoo Kowloon continually helped the police to solve mysterious cases, which made him known as a rising star. However, his impulsive personality dragged him into endless troubles. He got himself into fights with the Macau detective, as well as an American Army veteran Alexander who has a secret linkage to Kowloon’s background…

Fengfeng grew up in a lonely rural family. The only warmth besides Grandpa is He Hai. He Hai sees him every year, teaches him to exercise, fights military boxing, and follows the guidance of Grandpa and He Hai. The goal of the peak from small is to join the army to serve the country. After the death of his grandfather due to illness, he finally put down the last concern and joined the army. In the army, Feng Feng paid more sweat than ordinary people, in exchange for excellent results, and fellow villagers Zhang Kui and roommate Sun Fan struggled together, and also met the favorite female soldier Yu Man, four people joined together Special service team assessment.

Inspector Lam investigates the brutal murder of Tsui, a famous musician. Wong, the designated suspect, just spent 20 years in jail for the murder of Tsui's daughter but has always claimed his innocence.