Shen Yizhen accompanied Yin Hanwei to a high school reunion and learned the mystery behind the death of her mentor Song Yibing from her old classmates Chen Jia and Jiang Xucheng. Later, Chen Jia's body was found in the apartment. It seemed like a coincidence, but it also seemed to have been planned. In Shen Yizhen's investigation, characters emerge one after another, and the inextricably linked relationships become more and more complicated...