Where's Officer Tuba?

Tuba, a timid police officer, prefers the comfort of his trumpet in the police band to the dangers of patrolling the streets. However, his life takes a turn when he becomes embroiled in an extortion plot involving the reckless detective Rambo Chow. After Rambo suffers a fatal injury, he unexpectedly appears as a ghost, urging Tuba to fulfill his promise of revenge. With the support of his skilled partner, Cheung, Tuba gradually finds the courage to confront the criminals and honor Rambo’s memory.