Dedicated police detective Ma Zhe (Zhu Yilong) is assigned the case of a series of horrific murders in a rural Chinese town. As the investigation progresses, pressure from his superiors to find the suspected serial killer mounts, leading to a hasty arrest. But while his colleagues rush to celebrate, several clues push Ma Zhe deeper into a desperate investigation of his own – leading him into a dark world where mystery hangs over his every lead.