In 1980s Hong Kong, troubled youth Chan Lok-kwun, a mainland refugee, struggles to survive in the Kowloon Walled City by joining underground fights. Betrayed by crime boss Mr. Big while trying to buy a fake ID, he steals drugs from him and seeks refuge in the Walled City, where he encounters Cyclone, a compassionate yet authoritative crime lord.

Hong Kong Customs and Excise Department officers Chow Ching Lai and Cheung Wan Nam share a close mentor-student relationship. On a case involving seized smuggled arms, Chow is sent to take part in a joint operation with Interpol to capture a reclusive arms dealer. However, Cheung makes a drastic decision that further complicates the case.

In this classic whodunit, a police detective must rely on the only witness - a parrot, to catch the killer of an armed robber.

A fierce robber has plotted a major heist. But unfortunately, his plan was unintentionally foiled by two dispirited middle-aged best friends, and the stolen cash disappears.

Once famous for his quick blade, a retired assassin can no longer earn a living with his cut-throat skills. Summoned again, he partners with his chauffeur to carry out special missions – fullfilling the wishes of old people looking to kill themselves. When commissioned by a young girl who has been deserted by her parents and lover, the "Elderly's Angel" squad finds an arresting way to complete its task.

Lok is a recovering schizophrenic who yearns for love. One day, he encounters the young and beautiful Yan and quickly falls in love with her. The pair develops a relationship that is beyond their wildest dreams.