"Who killed Du Xiaofeng?" Du Xiaofeng is a female tattoo artist who was just released from prison. The first person to surrender was Liu Yijie, a prosecutor who convicted Du Xiaofeng herself. However, Meng Ye, the newlywed husband of the female prosecutor, confessed after waking up that he was the murderer. The only thing that can answer Du Xiaofeng's question is the 372 letters she wrote in prison... These letters are love letters she never sent; but after she was released from prison, these letters ignited the jealousy, lust, and feelings that they dared not face among the three... In the end, this love from hell finally led to an irreversible murder.