General Fu Li, a renowned warrior, redeemed a dancer named Qing Zhuang from the entertainment quarter. She bore a striking resemblance to his childhood sweetheart, Xin Niang, who had died four years prior. The only catch? Qing Zhuang was a simpleton—though obedient and well-behaved. What Fu Li didn’t know was that Qing Zhuang was actually a spy from the assassin organization "Song of the Swords", hired by enemy forces. Her mission was to gain his trust, gather military intelligence, and, if necessary, assassinate him to destabilize the border. Posing as a fool, Qing Zhuang grew close to Fu Li, but when he was ambushed outside, his subordinate Han Bing suspected her of leaking his whereabouts. Though Fu Li was brave, he wasn’t reckless—he repeatedly tested her, nearly exposing her identity. Fortunately, her shadow guard, Du Ya, intervened, helping her not only escape suspicion but also deepen Fu Li’s trust. However, Fu Li remained cautious, never fully letting his guard down. Then, news arrived that the emperor was critically ill, forcing Fu Li to rush to the palace. At the same time, Qing Zhuang received new orders—find a way to accompany him into the palace and steal the imperial defense plans.