A black diary passes from stranger to stranger, carrying the secret thoughts of its many owners. A job seeker plots to frame the rival of the person they secretly love, but after the rival drops out of school, guilt drives them to confess. Hairdresser Xu Xiaoyan is pranked by a colleague, so she sets a trap to get even, only to encounter a terrifying accident. Middle school student Hu Xiaolai sends an ambiguous text as a joke, sparking conflict between his parents and leaving his father injured. At last, a beautiful novelist receives the diary and turns its secrets into stories. But after submitting her work, she receives a blood-red warning: “The leaker dies.” The danger is far from over.
