Jiang Wanyun, the daughter of an imperial censor, marries into the residence of the General Who Guards the North. Three months into her marriage, she has yet to consummate her marriage with her husband, Lu Lin. She discovers that Lu Lin spends every night in the Buddhist shrine and realizes that a baby is hidden beneath its floor. The birthmark on the baby's shoulder is identical to Lu Lin's. After investigating, Jiang Wanyun is horrified to learn that the real Lu Lin died in battle three years ago, and that the man now posing as her husband is actually Ashina Lie, a Northern Di spy. She joins forces with Shen Yan, a junior official of the Court of Judicial Review, to gather evidence and lay a series of traps. In the end, she exposes a shocking conspiracy, brings Ashina Lie to justice, and wins back her freedom and a new life.