In Shangai, the "Green Dragon" threatens to kill Herbert Aboody, a rich exporter, unless he pays him 50,000 dollars. One of Aboody's secretaries calls inspector Wens for help. An amazing fact occurs, Wens kills Aboody and then disappears. What is the key to this mystery?
| Actor | Role |
|---|---|
 Hélène PerdrièreFloriane Aboody | Floriane Aboody |
 Paul BernardHerbert Aboody | Herbert Aboody |
 Maurice TeynacInspector Wens | Inspector Wens |
| PPierre JourdanSteve | Steve |
| SStanislas-André SteemanMatriche | Matriche |
| GGilberte ClairMona | Mona |
| KKrisha DuchesneLydia | Lydia |
 Ky DuyenCommissioner Whu | Commissioner Whu |
 Andrews EngelmannZetskaïa | Zetskaïa |
| RRobert LussacCommissioner Malaise | Commissioner Malaise |
| LLonne VooLotus | Lotus |
 Georgette Anys(uncredited) | (uncredited) |
| LLuong Van Yen(uncredited) | (uncredited) |
 Reggie NalderChinese taxi driver (uncredited) | Chinese taxi driver (uncredited) |