The court of Yun Kingdom is rife with hidden currents and political turmoil. Yi Jiaxin, the only daughter of Prince Pingyang, has just been officially appointed Crown Princess when she sets off for Wulong Mountain on a secret mission to investigate a series of bizarre incidents. Little does she know that the mountain is also home to the infamous Second Prince, Geshuyan, whose unpredictable cruelty strikes fear into everyone's hearts. She is lively and clever, possessing a rare Profound Yin constitution, while he is arrogant and untamable, suffering from the torment of fiery poison. From their very first meeting, they clash and match wits, yet a series of unexpected events forces them to work together. As the distance between them gradually narrows, the mysteries surrounding Wulong Mountain grow ever deeper. Court intrigues, old grudges, and an approaching conspiracy draw them into a whirlpool of fate from which there is no turning back.