In the bizarre Jinghai City, former crime team elite Lu Chenyuan and genius profiler Su Hui reunited because of the "Mirror Image Killer" serial case. Lu Chenyuan solved the puzzle of physics with cold logic, and Su Hui penetrated the abyss of people's hearts with his empathy. The two worked hand in hand through more than 20 mysterious cases such as "Glass Cage" and "Data Gluttony". The murderer tried the "sinner" with a strange ritual, and the mirror symbols left at the scene were entangled like a spider web, which actually implicated the dusty secrets of Lu Chenyuan's resignation and the dark past of Jinghai City's power elite. When reason and sensibility collide in a crime, they not only have to uncover the real culprit among the intertwined clues of truth and reality, but also face the mirror image of their own hearts - in the shadow of the foggy city, only their bond is the only echo that penetrates the darkness.