When the prized gun of his captain (Barry Wong) turns up missing, it's up to police officer Chow Sing-Sing (Stephen Chow) to retrieve it -- by going undercover as a high school student. Zeroing in on teenage triads, Chow navigates the halls with a helpful sidekick cop (Man Tat Ng). He also tries his best to make the grade with his pretty teacher, Miss Ho (Man Cheung). Gordon Chan directs this comedy.