The story follows Feng Yu Ji, a woman living under an assumed name, who returns to the Shen household posing as her twin sister—the Shen family’s young mistress—in an attempt to avenge her sister. She befriends Shen Tan Qian, the son of a wealthy merchant, and begins investigating the truth behind a long-suppressed murder case, ultimately revealing the true culprit and bringing him to justice. Throughout this journey, Feng Yu Ji and Shen Tan Qian move from mutual distrust to open honesty and, ultimately, heal one another. With courage, wisdom, and the strength of their self-sacrificing love, they bring the truth to light. As the truth unfolds, their joint efforts also put an end to the Shen family’s opium trade with the Japanese, gradually ending the city’s opium addiction and ushering in a new era of science and civilization.