Hong Kong Film: Starting with a Detective Agency

I once solved the Xiangjiang Demon Police Case. I've solved locked room murders. I once solved the case of serial murder of prostitutes in the middle of the night. … The most rigorous organization with the best crime-solving equipment in the world was defeated by me. My name is Xu Lang, and many people like to call me the King of Crime Solvers. Some people also call me a billionaire, the person with the highest IQ in the world, the Supreme Lover... Actually, I'm just a private detective. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.