Chief B (Danny Lee) is an unconventional CID member who relies more on instincts rather than by the book to resolve situations. He's a down-to-earth fellow who's a mamma's boy not too well-educated and an outstanding member of the CID. Police Officer Kit (Eddie Chan) has just been promoted from the rank-and-file to CID and at the same time is studying for the test to become an Inspector. Chief B takes him under his wings to investigate numerous gang-related cases. Kit previously a by-the-book type of police officer learns a lot from Chief B.