Lu Zhaoyao blew up the criminal investigation archives with his own hands. There were no casualties at the scene, only scorched earth and a blood-stained anonymous letter: "What you investigated should have been buried long ago." He is the calmest serious case team leader in the bureau. She is a genius forensic doctor who was suspended after graduating from the police academy. She was his only witness in the arson case three years ago, and she was also his only stain. When the underground black market began to reappear the murder weapons of seven unsolved cases, and when each corpse had a bronze medal with "JT" engraved on its heart, Lu Zhaoyao knew that what was blown up was not the files, but the iron cage that locked the truth. And Jiang Jintang was walking towards him from the darkness, clutching the original dossier that should have been burned to ashes.