A mercenary of ten years in the apocalypse, Lin Su, transmigrates into Jiang Yueyao, the arrogant second young mistress of Fengsui City in a matriarchal romance novel. The original owner relied on favor to forcibly marry Song Jinze, the defeated peace-offering young lord of Qianshuo. Song Jinze endured and married into the family as a consort, single-mindedly seeking revenge for his brother and waiting for an opportunity to eliminate Jiang Yueyao. Relying on her apocalyptic combat skills, Lin Su defuses assassinations multiple times and repeatedly protects Song Jinze by accident, making him change his view of this "good-for-nothing" young mistress. When the mastermind behind the scenes is exposed, Song Jinze's emotional knots dissolve, and he begins pursuing his wife. Song Lie leads troops to the border, framing Song Jinze for treason. Jiang Yueyao risks her life to rescue him and clears his grievances. The two join forces to quell the civil unrest in Qianshuo, bring peace between the two cities, join hands to suppress bandits and comfort the people, put aside old hatreds to stay together, and govern the two cities jointly.