Where's Officer Tuba

Tuba (Sammo Hung) is a policeman, but because of his timid character, he spends his days in the Police Band as a tuba player. Inspector Chow (David Chiang) sees the potential in Tuba and arranges him to investigating the case together. Unfortunately, Chow gets killed at work, but his ghost helps Tuba to crackdown on the villains and justice is brought back. Tuba even wins his girl (Joey Wong Cho-Yin) with his returned confidence!