Shades of Truth

Shades of Truth (Traditional Chinese: 水滸無間道; literally Water Margin's Unceasing Path) is a 25-episode television comedy-drama from Hong Kong.

900 years later after they reincarnate to Hong Kong, they meet again as the young patrol officer Dung Chung Cho (Julian Cheung) and top police official TC Lam (Wong Hei).

Under the orders of police official KY Wong (Gordon Liu), Dung Chung Cho is sent to the triad controlled by Sung Po (Yuen Wah) as an undercover.

After a slight injury on the head, Dung Chung Cho gains his past memories as Wu Song 900 years ago and tries to convince TC that he is his long lost brother Lin Chong.

How come the police can never gather enough information to capture the triads for holding illegal businesses and charge them for attempting to murder so many people?