This drama follows Fan Changyu, a butcher’s daughter, and Xie Zheng, a fallen noble seeking revenge. Their fake marriage turns into true love, but war tears them apart. Determined, Fan Changyu wields her butcher’s knife on the battlefield, searching for justice and her husband. Meanwhile, Xie Zheng reclaims his title, fighting to protect his country and love. Reunited in battle, they stand together, defying fate, uncovering the truth, and returning home without forgetting their vows.

Blood River is the realm's most feared assassin guild, jointly run by the Su, Mu, and Xie clans. They can strike royals in court and crush great sects in the wild. When the patriarch is poisoned on a mission, the three clans vie for the top seat. Su Muyu leads the Spider-Shadow unit and shields the dying leader on the road to a cure. He clashes with elder Su Zhe and old friend Su Changhe, and meets master healer Bai Hehuai. After brutal power struggles, Su Changhe becomes new patriarch and Su Muyu heads the Su clan. They launch the "Other Shore Plan" to drag Blood River out of the shadow and forge a new destiny, free from being anyone's blade.