22-Year-old Lu Shen entered the police force with excellent results in criminal investigation. His first case was a murder case in a western suburbs villa - Li Wen, the wife of entrepreneur Zhao Mingyuan, died at home. The silver buttons and black ties at the scene were not only similar to the "old red raincoat serial case", but police uniform fibers were also detected, casting doubt on the case. Lu Shen was entrusted with the important task because of his keen insight, but he fell into layers of puzzles: the skin tissue under the dead man's fingernails, the black SUV whose GPS had been tampered with, the suit pants that mysteriously disappeared, and the warnings from anonymous text messages all pointed to a well-planned conspiracy. He saw through Wang Zhiqiang's trick of pretending to be Zhao Mingyuan to create an alibi, but found that Wang Zhiqiang was just a pawn, and there was a greater darkness behind his "Red Raincoat Case Repeat Plan". After 40 years of working as a police officer, Lu Shen struggled with murders and undercurrents: chasing down killers who imitated crimes, solving secret room cases involving political and business interests, being threatened and framed for investigating old cases, and witnessing the sacrifice of his comrades. It was not until the eve of his retirement that he discovered that the clues to Li Wen's case were closely intertwined with the traces of the real culprit in the Red Raincoat case. The end of his lifelong pursuit of the culprit was the starting point of unraveling all the mysteries.
