Bun, a schizophrenic, former police inspector comes out of retirement to help a rookie detective solve a complex murder case involving a missing colleague and a suspected policeman suffering from a multiple personality disorder.
You can now watch Mad Detective online on the following streaming providers in the United States.
| Directing | Johnnie To | Director |
| Directing | Wai Ka-fai | Director |
| Writing | Wai Ka-fai | Screenplay |
| Writing | Au Kin-yee | Screenplay |
| Production | Johnnie To | Producer |
| Production | Wai Ka-fai | Producer |
| Camera | Cheng Siu-keung | Director of Photography |
| Art | Raymond Chan Kam-Ho | Art Direction |
| Costume & Make-Up | Stanley Cheung Sai-Kit | Costume Design |
| Costume & Make-Up | Midco Chu Wai-Fong | Makeup Artist |
| Editing | Tina Baz | Editor |
| Sound | Xavier Jamaux | Original Music Composer |
| Production | Chiu Chi-Shing | Unit Manager |
| Art | Raymond Chan Kam-Ho | Production Design |
| Costume & Make-Up | Mark Garbarino | Makeup Artist |
| Sound | Martin Richard Chappell | Sound Designer |
| Production | Charles Heung Wah-Keung | Executive Producer |
| Production | Kuk Kok-Leung | Line Producer |