During the Republic of China period, Feng Xiao (played by Cheng Yufeng), the adopted son of a wealthy businessman, and Lin Wanxiu (played by Liu Meiqi), the adopted daughter of a warlord, were husband and wife, but in the turbulent times, they each served their own masters. They loved each other but had to hide their identities as assassins from each other. As the conflict between the wealthy businessman and the warlord continued to deepen, the two were forced to face a situation where the couple loved and killed each other, but their love for each other eventually resolved the misunderstanding, allowing the two to reconcile and join forces to smash a conspiracy to resell national treasures, becoming a pair of assassins that the evildoers feared.