During a routine autopsy, top forensic pathologist Gu Yan discovers a set of unusual marks that closely match those from the “Trace-Free Serial Murders,” a case that shocked the entire city ten years ago. The case went cold because of the technological limitations of the time, but now he decides to reopen the investigation. Every new body he examines is like a coded letter from the dead. As the fragments of evidence gradually form a picture, they reveal a criminal network spanning both politics and business. Meanwhile, copycat crimes, internal leaks, and the mysterious deaths of key witnesses follow one after another. Gu Yan is forced to race between the autopsy table and crime scenes, using the precise language of science to give voice to the dead’s unfinished words, until at last he draws the “Cleaner” hiding behind the perfect crimes out into the open.
