During the Tang Dynasty, Prince Jian Li Yong conspired with the corrupt minister Ma Lifu to exploit the emperor's critical illness. They placed Crown Prince Li Chun under house arrest and seized control of the court, plotting a coup. General Lin Yan of the Imperial Guards and Chen Li, the chief constable of the Nine Gates, found themselves entangled in this dangerous conspiracy. Compelled to act alone, Lin Yan embarked on a perilous mission to rescue the imprisoned crown prince. Utilizing her extraordinary martial skills, she executed a daring nighttime prison break, narrowly escaping death in the process.