- **Mysterious Murders**: A string of murders has taken place in Binhai City. The victims are all young women who died from insulin overdoses. Each crime scene is meticulously arranged to make them appear to be confessing, and the killer leaves behind notes taunting the police with the “Seven Deadly Sins.”
- **Genius Profiler**: Ke Wenrui, an expert in criminal psychology, is urgently recalled to help solve the case. Past trauma drove him away from the police force, but his old partner, Cheng Feng, persuades him to return.
