A small film scriptwriter found a treasure map among his grandfather's belongings by accident, and the location of the treasure is underneath the prison in Chilang Bay.

Brother Shan, the undercover in the Major Crime Unit in West Kowloon sent a tip to Sir Wei, the senior inspector saying that the biggest drug trafficker in Hong Kong, “Mr. Jin” would deal the largest amount of drugs of this year himself with the money involved being 20 million dollars. However, this time, the deal is actually a strategy by the drug traffickers to lure the police undercover out. The undercover Brother Shan was accidentally exposed and the drug traffickers were chasing him in full force. On the other hand, suddenly, his undercover identity was no longer recognized and he got caught in the conflict between the good and the evil. Brother Shan needs to “prove his innocence” in time and smash the scheme of the big drug trafficker “Mr. Jin".