After her father's death, Chu Yu marries into the Wei family to investigate mysterious events. As she grows close to Wei Yun, the last surviving member of the family, they face numerous challenges together, navigating their evolving feelings while working to uncover the truth and protect their homeland.

楚瑜的父亲战死沙场，身负重伤的兄长向她透露此中之事绝不简单，她立誓定要将真相查明。卫家在一场战役中遭遇惨败，卫家仅小儿子卫韫一人存活。楚瑜嫁入卫家，以已逝大哥遗孀的身份展开调查，起初卫韫心怀戒备，在之后的相处中被楚瑜所打动。两人之间情愫渐起，然而伪造的“叔嫂”身份却成为了阻碍。他们历经生死考验，共同抵御外敌，深入调查真相，携手守护大好山河。