Shen Yan, daughter of a military family, disguised herself as a man and served the Ninth Prince, Xiao Ke, as the emperor's ruthless enforcer for five years. She shielded him from poisoned arrows, sacrificed her right arm, took drugs that robbed her of her voice, and killed everyone he wanted dead. In return, she was erased from the official records, silenced, and burdened with infamy. Five years later, she returned to the capital carrying the head of a rebellious prince. Instead of the reward she expected, she received an imperial decree accusing her of crimes. In the death prison, she finally understood that the man had never wanted a loyal subject. He wanted a caged bird that could never fly away. She tore off her embroidered flying-fish uniform and struck the Great Ancestor's Dengwen Drum, which had remained silent for forty years, demanding justice directly from the emperor. Amid the Jiangnan rain, she stepped back three paces from the emperor kneeling before her and performed the humble salute of a commoner. I, the commoner Shen Yan, bow before Your Majesty. Long live the Emperor!