- HD 1080
- Runtime: 91m.
- Status: Released
1
- Languages: zh
- Country: Hong Kong
- Director: Johnnie To Kei-Fung, Wai Ka-Fai
- Stars: Sean Lau Ching-Wan, Andy On Chi-Kit, Gordon Lam Ka-Tung, Kelly Lin, Lee Kwok-Lun
- Production_studio: Milkyway Image
- Slogan: I can see a person's inner personality.
- providers: AMC Plus Apple TV Channel, AMC+, IFC Films Unlimited Apple TV Channel
- The Mad Detective is featured in the top rankings of 2007
- #15 in Top Action Movies of 2007
- #17 in Top Crime Movies of 2007
- #17 in Top Thriller Movies of 2007
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.