Synopsis：As a forensic doctor, Gao Sihai's grandfather adhered to his principles and worked hard to find clues to the truth of the case, but he was framed by others, leading to errors in the test results. He endured a bad reputation for thirty years, gave up the forensic work he loved, and eventually suffered from Alzheimer's disease. Gao Jianshe, the deputy captain of the criminal police brigade, died heroically while investigating a case 20 years ago. The case was never solved and was later suspected to be an unjust case, nearly tarnishing his heroic image. His grandson, Gao Feng, who was about to leave the police force, decided to stay due to a case involving the reputation of his grandfather and father. To uncover the truth, he fought alongside the police, overcoming numerous difficulties, enduring immense pressure, and revealing the truth of a long-concealed case. The criminals who had evaded justice for 30 years were brought to trial, bringing solace to the spirits of his grandfather and father in heaven.