Nine years ago, Lingchuan City was rocked by the “Deadly Reflection” serial locked-room murders. The killer used mirrors as part of a ritual, removing the victims' eyes in sealed rooms and leaving no fingerprints, footprints, or murder weapons behind. Seven people died under bizarre circumstances. Shen Yanci, head of the task force, disappeared after an explosion while pursuing the killer, and the case became a permanent cold case. Nine years later, Shen Yanci returns to the Criminal Investigation Bureau as a trace evidence consultant who has “rejoined the force after losing his memory.” At his side is a quiet young partner, Lu Zhizhe, an expert in criminal psychology and profiling. One reads the traces; the other reads people. From mutual suspicion to standing by each other through life and death, they solve one bizarre case after another: murders recreated through mirrors, corpses sealed inside an old building, a box of bones at the bottom of a river, names erased from the archives. Every case points to the lingering shadow of the mirror murders from nine years earlier. The killer never disappeared. Hiding beneath the order of society, he continues to reap so-called “sinners” in the name of “the Cleaner.” As the clues are painstakingly uncovered, Shen Yanci's lost memories gradually return. The truth about the explosion, his undercover identity, a mole in the bureau, the old sins of his family, and an original sin behind a chain of murders spanning twenty years all come to light. Behind the mirror is no evil spirit, but an avenger consumed by the system and human nature. Shen Yanci and Lu Zhizhe are the two most important pieces on the killer's chessboard. With traces as their blades and psychology as their shield, they hunt the killer through a fog built of lies and seek the truth at death's door. In the end, they tear away every disguise, letting the embers buried for nine years illuminate every crime and truth that was concealed.
