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.

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.

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.

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, Ching-lai is sent to take part in a joint operation with Interpol to capture a reclusive arms dealer. However, Wan-nam makes a drastic decision that further complicates the case.

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.

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