Liu Ruyan, a border general who disguised herself as a man, was invincible on the battlefield, but she had to return to Beijing to participate in the draft. She used "Sun Tzu's Art of War" to deal with her mother's difficulties, and "Thirty-Six Strategies" to deal with her sisters' frame-up. The emperor saw through her identity, but asked her to become his secret guard - because the real enemy was not on the battlefield, but under the dragon's throne.
