In her past life, Zhu Yinyin was used as a substitute by the Third Prince Pei Chi and died a miserable death. Reborn back to the day of her imperial marriage decree, she publicly refuses the marriage and escapes the capital with the help of medical officer Wei Zhao, heading to Taicang. Relying on her meticulous mind, she cracks successive suspended cases and becomes a respected guest counselor in Taicang. The paranoid Pei Chi pursues her to Taicang, manufacturing serial murders to pressure her. Refusing to back down, Zhu Yinyin joins forces with Wei Zhao and her repentant brother to hunt down the killers, shattering Pei Chi's distorted obsession. Ultimately, she breaks free from her destiny and welcomes a fulfilled new life with Wei Zhao in Taicang.