Penny and Wendy originally are co-workers and best friends until Wendy is promoted. Penny feels that she is getting old and can't compete with Wendy, she leaves Hong Kong, takes snake blood to cleanse herself, and then returns to Hong Kong for revenge.
Unfortunately the movie Evil Instinct is not yet available on HBO Max.
| Directing | Barry Chu | Director |
| Writing | Barry Chu | Writer |
| Writing | Lu Bing | Writer |
| Production | Ricky Wong Ga-Kui | Producer |
| Crew | Joe Chan Kwong-Hung | Cinematography |
| Lighting | Coffee Hui Tak-Cheung | Lighting Director |
| Art | Joe Hau Wing-Choi | Art Direction |
| Editing | Grand Yip | Editor |
