A troubled boy who seeks escape becomes a man through a miraculous growth formula but encounters a new troubles when the formula won't quit.

As a director faces a series of setbacks in life including debt and divorce, his elderly father suddenly regains his youth.

Mike, Jean, Shoot and Q are a professional robbery gang working for Uncle Lam. Q loves his girlfriend Bo who loves decisive men and luxury life. Shoot loves exotic fishes and Jean. Jean loves Mike, but he is married to another woman and has a young son. Uncle Lam loves good meals and big money. After finishing successfully the most recent job for Uncle Lam, Mike and his team want to take a break. Uncle Lam insists that they take one more job, which is to rob a triad boss Chicken Sam who loves diamonds in the very literal sense of the word. The robbery doesn’t go too smooth; moreover, Tom Wai, a police officer who loves his job, is getting closer and closer…

Tensions arise when Jack Chan, a spineless constable who regards his work as a job but not a career, is partnered with an energetic and conscientious policewoman, Man Liu. When a serial killer emerges in Hong Kong, Man Liu swears to catch him. Jack is impressed by her bravery and decides to secretly protect her.