Lu Chengyan, a driven detective from 2025, is unexpectedly reborn in an alternate ancient world, while the System he carries with him falls dormant. Drawing on his forensic knowledge and expertise in trace evidence, he secretly helps his constable parents solve one baffling case after another. People come to call him the “Little Divine Constable,” but his achievements are always kept under wraps.
At eighteen, fed up with the county office’s evasive and halfhearted approach to investigations, Lu Chengyan retires to the outskirts of the city with the reward money he has saved, hoping only to live in peace. But his quiet life is shattered by six bizarre connected cases erupting in the imperial capital. Murders multiply and panic spreads, while the emperor urgently searches for a hidden expert.
Princess Zhao Qingyan, the emperor’s seventh daughter, once witnessed young Lu Chengyan’s uncanny talent for solving cases ten years ago. Disguised, she joins the search for gifted people. When the group passes through a county town, they find a scholar’s drowning case stalled. Lu Chengyan, who has come down from the hills to buy paper and ink, casually suggests, “Look into the silk-weaving method and the residue beneath the fingernails,” inadvertently revealing his abilities.
After Commandant Zhou urges him to join the investigation, Lu Chengyan uses modern forensic techniques to solve three bizarre cases in succession. The Seventh Princess becomes certain that he is the astonishingly gifted boy she met years ago. But when someone wearing the same blue cotton robe impersonates him and frames an innocent person, Lu Chengyan realizes that the minor cases are all connected to the major crimes in the capital, concealing a conspiracy that could shake the court.
To catch the real culprit and protect those around him, the retired master detective finally relents: “We’re going to the imperial capital.” The clash between modern criminal investigation, ancient occult arts, and court intrigue begins.
