Set in the late Ming Dynasty, Brotherhood of Blades tells of three close friends (Chang Chen, Wang Qianyuan, and Li Dongxue) who serve as Jinyiwei guards. They are dispatched by a palace eunuch (Nie Yuan) to hunt down Wei Zhongxian (Jin Shijie), a eunuch politician who had been forced to resign from his influential post and exiled from Beijing. The Jinyiwei brothers return successfully from their quest, only to find that their task was but the beginning of a strange conspiracy.
