"Stain" is a gripping criminal investigation mystery novel that tells a series of suspenseful cases. As the case progressed, the police gradually discovered that behind every seemingly ordinary crime, there were more complex and unfathomable mysteries hidden. The murderer skillfully manipulates time and memory, sometimes hiding, sometimes calmly and provocatively, and every case has dark and unknown clues. The process of solving the case is like a game with fate. The truth becomes increasingly blurred, and the boundaries between justice and malice become increasingly blurred. As layers of fog were lifted, the police had to face a more sinister fact: the truth may have been lost in the chaos of time. Are you ready to follow them into this endless psychological warfare and intellectual game?