December 1924, Karl Denke fails to smite Vincenz Olivier with a pickaxe. He would have been his 31st victim. The film thus reconstructs the mind, motivation, and psyche of its main character in intense dialog between him and the inspector.
大一新生李珍欣因为想成为一名语言治疗师,来到大学后发现同学对她都很不友好,除了一名叫尤美的学生,两人很快成为了好朋友。珍欣在入住的宿舍楼不断听到奇怪的声音,还有袭击珍欣的黑衣人,幸好最后被尤美救出,与此同时尤美的身份也随之被解开…