By a strange twist of fate, dutiful Hong Kong policeman Dan saves the life of the leader of a violent gang of armed robbers. When they commit another crime, Dan is determined to put an end to their activities. He works with the leader, whom the gang had betrayed, to engineer a plan to wreak havoc within the gang and let the gangsters kill one another. But it becomes increasingly obvious to Dan and to his colleagues that Dan is suffering from a severe mental disorder, and Dan finds that instead of upholding the law as a righteous police officer, he has now become a fugitive wanted for murder.
Is That Demon Within on Netflix? Unfortunately the movie That Demon Within is not yet available on Netflix.
| Directing | Dante Lam Chiu-Yin | Director |
| Writing | Dante Lam Chiu-Yin | Writer |
| Writing | Jack Ng Wai-Lun | Writer |
| Production | Candy Leung Fung-Ying | Producer |
| Editing | Patrick Tam Kar-Ming | Editor |
| Crew | Chi Shui-Tim | Pyrotechnician |
| Production | Kathy Wong Ka-Yi | Assistant Production Manager |
| Directing | Yu-Shan Li | Continuity |
| Camera | Kenny Tse Chung-To | Director of Photography |
| Crew | Kenny Tse Chung-To | Cinematography |
| Production | Cheung Hong-Tat | Co-Producer |
| Production | Stephen Lam | Co-Producer |
| Production | Albert Lee | Producer |
| Production | Ren Yue | Producer |
| Production | Song Dai | Executive Producer |
| Production | Sze Yeung-Ping | Executive Producer |
| Production | Albert Yeung | Executive Producer |
| Sound | Leon Ko | Music |
| Sound | Leon Ko | Original Music Composer |
| Editing | Curran Pang | Editor |
| Art | Lee Kim-Wai | Art Direction |
| Costume & Make-Up | Stephanie Wong Ka-Bo | Costumer |
| Costume & Make-Up | Cherlynn Koh | Special Effects Makeup Artist |
| Costume & Make-Up | Middi Yau | Special Effects Makeup Artist |
| Directing | Jay Cheung | First Assistant Director |
| Directing | Fan Wai-Chung | Assistant Director |
| Visual Effects | Raymond Wai-Man Leung | 3D Artist |
| Sound | Viola Chan | Sound Effects Editor |
| Sound | Phyllis Cheng | Sound Designer |
| Sound | Ip Siu-Kei | Sound |
| Sound | Mandy Kwan | Sound Effects Editor |
| Sound | David Wong | Sound Effects Editor |
| Editing | Stéphane Ma | Colorist |
| Crew | Devil Siu-Chung Siu | Set Runner |
| Lighting | Hoi Yan Chan | Electrician |
| Lighting | Wong Wai-Chuen | Electrician |
| Crew | Huan-Chiu Ku | Stunts |
| Crew | Phillip Chung-Fung Kwok | Stunts |
| Crew | Lee Chi-Kit | Stunts |
| Crew | Pok Yan Leung | Stunts |
| Crew | Gobi Ng | Stunts |
| Crew | Chi-Man Wong | Stunts |
| Crew | Lau Man-Yue | Stunt Coordinator |
| Writing | Dante Lam Chiu-Yin | Idea |
| Writing | Dante Lam Chiu-Yin | Screenplay |
| Writing | Dante Lam Chiu-Yin | Story |
| Writing | Jack Ng Wai-Lun | Idea |
| Writing | Jack Ng Wai-Lun | Story |
| Writing | Jack Ng Wai-Lun | Screenplay |
| Directing | Cheung Tso-Ping | Assistant Director |
