Modern expert Mingyue unexpectedly time-travels and becomes the new primary wife destined to marry the Ninth Prince, Xiao Yintang. Knowing the historical trajectory, she only wants to live a peaceful life and avoid the imperial succession struggles to preserve herself. Unexpectedly, on their wedding night, Xiao Yintang can hear her inner thoughts. While Mingyue appears dignified and obedient on the outside, inwardly she constantly complains about the situation, repeatedly leaking future crises. From his initial shock and suspicion, Xiao Yintang gradually recognizes the hidden risks of the Eighth Prince's faction, wakes up, and chooses to stand with the Fourth Prince. Putting aside their estrangement, the couple works together to reorganize the prince's estate, develop trade and livelihood, and use their wisdom to resolve the heavy crises in the inner courtyard and the imperial court.