# Mad Detective (神探)
**Mad Detective** (神探) is a 2007 Hong Kong crime thriller co-directed by [Johnnie To](https://www.edgepedia.org/johnnie-to) and Wai Ka-fai, in which a retired detective who sees people's "inner personalities" helps investigate a missing-gun case whose chief suspect harbors seven such personalities. It was written by Wai Ka-fai and Au Kin-yee, produced by One Hundred Years of Film with Milkyway Image, and stars Lau Ching-wan, Andy On, Gordon Lam Ka-tung, and Kelly Lin.[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) • [2](https://www.rottentomatoes.com/m/mad_detective)
| Key fact | Detail |
|---|---|
| Original title / year | 神探 (San taam), 2007, Hong Kong, Cantonese, 91 minutes[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) |
| Directors / writers | Directed and produced by Johnnie To and Wai Ka-fai; screenplay by Wai Ka-fai and Au Kin-yee[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) |
| Lead cast | Lau Ching-wan (Chan Kwai-bun), Andy On (Inspector Ho Ka-on), Gordon Lam (Ko Chi-wai), Kelly Lin (May Cheung)[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) • [3](https://www.imdb.com/title/tt0969269/fullcredits/) |
| Festival premiere | Venice Film Festival, September 6, 2007; Hong Kong release November 29, 2007[4](https://www.imdb.com/title/tt0969269/releaseinfo/) |
| Awards | Best Screenplay at the 27th Hong Kong Film Awards (2008) and the Hong Kong Film Critics Society award; 8 Hong Kong Film Award nominations[5](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/WAI-Ka-fai_c.pdf) • [6](https://yule.sohu.com/20080327/n255945011.shtml) |
| Reception | 80% Tomatometer (20 reviews) and 85% audience score on Rotten Tomatoes; Hong Kong box office over HK$10 million[2](https://www.rottentomatoes.com/m/mad_detective) • [7](https://ent.sina.cn/review/media/2008-04-06/detail-iawzunex7652114.d.html?wm=3049_0015) |
| Follow-up | Wai Ka-fai directed *Detective vs. Sleuths* (神探大战, 2021), again with Lau Ching-wan, which he described as a different type of film, not a sequel[8](https://www.jiemian.com/article/7732872.html) |
## Spoilers
### Premise and plot
The case begins when two plainclothes officers chase a suspect into a wooded area. Only Ko Chi-wai (Gordon Lam) returns; his partner disappears along with his service gun, which is later used in a series of robberies and killings.[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) • [9](https://www.screendaily.com/mad-detective/4034692.article) Inspector Ho Ka-on (Andy On), assigned to the investigation, seeks help from his former superior Chan Kwai-bun (Lau Ching-wan), a detective who left the force after being discharged on grounds of mental illness.[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) • [10](https://www.lovehkfilm.com/reviews_2/mad_detective.htm)
Bun's gift is that he can see a person's "inner personalities" as separate people whom no one else perceives. When he meets Ko Chi-wai, he immediately sees seven personalities in him, including a woman, a cowardly glutton, and a sadistic strongman; in a restaurant scene the film shows all seven on screen at once, and Bun is the only character who can see them.[9](https://www.screendaily.com/mad-detective/4034692.article) Bun's methods are unorthodox: he investigates by role-playing, stabbing a dead pig to reconstruct a killing and zipping himself into a suitcase that is thrown down a staircase to experience a victim's death.[10](https://www.lovehkfilm.com/reviews_2/mad_detective.htm) He also tells Ho to solve cases with the right brain rather than the left, favoring empathic imitation over deduction.[11](https://www.chinawriter.com.cn/n1/2017/0321/c404004-29158983.html)
The film reveals the truth of the gun case early and treats it as a starting point rather than a mystery to be solved. The Hong Kong Film Archive's synopsis notes that the solution is evident from the start and serves instead as a way into a tangled portrait of human nature, with the characters' split personalities made visible through composition and editing.[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) As Bun's chaotic methods frustrate Ho, they expose a hidden personality in Ho himself, that of a frightened little boy.[9](https://www.screendaily.com/mad-detective/4034692.article)
## Style and visual approach
The film blends real and imaginary characters on screen without signaling which is which, making subjective perception its central device.[9](https://www.screendaily.com/mad-detective/4034692.article) Cinematographer Cheng Siu-keung, a longtime To collaborator, shot the film in steely blue chiaroscuro, and the nervous editing keeps the pace compressed.[9](https://www.screendaily.com/mad-detective/4034692.article) The climax is a gunfight in a room of mirrors that the Film Archive identifies as drawing on the mirror-house shootout of [Orson Welles](https://www.edgepedia.org/orson-welles)'s *The Lady from Shanghai* (1947) and the design of *Long Arm of the Law* (1984).[1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) The final scene leaves Inspector Ho rearranging the guns among the bodies, trying to construct a story that holds together.[11](https://www.chinawriter.com.cn/n1/2017/0321/c404004-29158983.html)
## Production context
Mad Detective was made at a milestone for its studio. Wai Ka-fai and Johnnie To founded Milkyway Image in 1996, and the two had co-directed commercial comedies such as *Needing You* (2000) and *Fat Choi Spirit*-era hits before the 2003 *Running on Karma* won them the Hong Kong Film Awards for Best Film and Best Screenplay.[5](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/WAI-Ka-fai_c.pdf) • [12](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/Johnnie-TO_c.pdf) To had also formed the production company One Hundred Years of Film in 2000 with other directors, and it is credited as the film's producer.[12](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/Johnnie-TO_c.pdf) • [1](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html) Commentators writing at the time of release described the film as a summation of Milkyway's first decade, and it was released in the year marking the company's tenth anniversary.[13](https://yule.sohu.com/20080318/n255774256_4.shtml) • [14](https://funscreen.tfai.org.tw/article/38958)
The missing-gun premise had a real-world echo: a 2001 case in which a Hong Kong police officer was killed and his gun, later used in further killings, became known as the "ghost gun." Two directors eventually dramatized the affair, Dante Lam in *The Demon Within* (2014) and To and Wai in *Mad Detective*.[11](https://www.chinawriter.com.cn/n1/2017/0321/c404004-29158983.html)
## Release and reception
The film premiered in competition at the [Venice Film Festival](https://www.edgepedia.org/venice-film-festival) on September 6, 2007, screened at Toronto and other festivals, and opened in Hong Kong on November 29, 2007.[4](https://www.imdb.com/title/tt0969269/releaseinfo/) It reached mainland Chinese theaters in February 2008, where its ending was altered for the mainland version, and received eight nominations at the 27th Hong Kong Film Awards.[6](https://yule.sohu.com/20080327/n255945011.shtml) Wai Ka-fai won the Best Screenplay award at that ceremony for the film.[5](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/WAI-Ka-fai_c.pdf) In North America, IFC First Take gave it a limited theatrical release on July 18, 2008, grossing $4.6 thousand in the United States.[2](https://www.rottentomatoes.com/m/mad_detective)
Critics responded to its strangeness. Manohla Dargis of *The New York Times* gave it 4.5 out of 5, calling it "insanely inventive and entertaining," and Ty Burr of *The Boston Globe* rated it 3 out of 4 as "a stylishly funky Hong Kong thriller."[2](https://www.rottentomatoes.com/m/mad_detective) The Hong Kong Film Archive's retrospective notes place the film's detective figure at the opposite extreme from the cool, Holmes-like inspectors of earlier Hong Kong cinema, describing him as a kind of madman-superman who dissects not only the case but human hearts.[15](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs.html)
## Legacy
The film became a reference point in Hong Kong's detective-crime cycle. In 2022 Wai Ka-fai directed *Detective vs. Sleuths* (神探大战), again starring Lau Ching-wan as a mentally ill ex-detective; Wai said publicly that it was not a sequel to *Mad Detective*, calling the earlier film closer to an auteur film and the new one a commercial picture, but the shared title, lead actor, and schizophrenic protagonist invited comparison.[8](https://www.jiemian.com/article/7732872.html) The Museum of Modern Art screened the film in 2024 in its retrospective of Johnnie To, describing it as a character study that interweaves subjectivity and objectivity and highlights the thin line between madness and genius.[16](https://www.moma.org/calendar/events/9895)
## References
1. [神探, Hong Kong Film Archive program note](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs-film06.html)
2. [Mad Detective, Rotten Tomatoes](https://www.rottentomatoes.com/m/mad_detective)
3. [Mad Detective (2007) Full cast & crew, IMDb](https://www.imdb.com/title/tt0969269/fullcredits/)
4. [Mad Detective (2007) Release info, IMDb](https://www.imdb.com/title/tt0969269/releaseinfo/)
5. [香港影人小傳：韋家輝, Hong Kong Film Archive](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/WAI-Ka-fai_c.pdf)
6. [《神探》内地版结局尽改 长沙上映褒贬参半, Sohu Entertainment](https://yule.sohu.com/20080327/n255945011.shtml)
7. [第27届香港电影金像奖终极猜想, Sina Entertainment](https://ent.sina.cn/review/media/2008-04-06/detail-iawzunex7652114.d.html?wm=3049_0015)
8. [香港神探闯内地, Jiemian News](https://www.jiemian.com/article/7732872.html)
9. [Mad Detective review, Screen Daily](https://www.screendaily.com/mad-detective/4034692.article)
10. [Mad Detective (神探) (2007) review, LoveHKFilm](https://www.lovehkfilm.com/reviews_2/mad_detective.htm)
11. [香港，我的枪丢了，《神探》中的社会寓言, China Writers Association website](https://www.chinawriter.com.cn/n1/2017/0321/c404004-29158983.html)
12. [香港影人小傳：杜琪峯, Hong Kong Film Archive](https://www.filmarchive.gov.hk/documents/6.-Research-and-Publication/06-02-Filmmakers-Search/Chinese/Johnnie-TO_c.pdf)
13. [《神探》出马拯救濒死港片, Sohu Entertainment](https://yule.sohu.com/20080318/n255774256_4.shtml)
14. [重探《神探》, 放映週報](https://funscreen.tfai.org.tw/article/38958)
15. [瑰寶情尋──聲影「留」傳 II, Hong Kong Film Archive](https://www.filmarchive.gov.hk/sc/web/hkfa/pe-event-2021-tat2-fs.html)
16. [Mad Detective (神探), MoMA](https://www.moma.org/calendar/events/9895)
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*Topic: Encyclopedia › Arts and culture › Screen and stage › Film and television › Films and standalone screen works › Individual films by title and year › Crime, thriller, and mystery films (individual works) › 2005–2009 films › Released 2005 to 2007*
*Initially written Oct 3, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026; Nov 1, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license