The seemingly comely and frail follower Li Zinian follows Kitamiya Ze, the prince of Pingxi who is admired by everyone, and goes south to investigate the case of smuggling official salt... An old priest who died mysteriously, a childhood friend who met suddenly, the case becomes more and more confusing, and the two discover that everything behind it is actually related to the person who holds huge power behind the palace wall, and the dynasty can change in an instant...