Ye Lingshuang, an ordinary maiden who grows up with the beloved youngest princess of the grasslands Qi Hairui / Zhuyan. The girls become best friends, and Ye Lingshuang swears allegiance to the princess. Unfortunately, the Kingdom of Zhao’s ambitious ruler Yu Xiuming conspires a plan to take over the grasslands, which eventually leads to Qi Hairui’s suicide. Ye Lingshuang vows to avenge the death of her princess, and enters Yu Xiuming’s palace under a new identity. The emperor develops an interest in Ye Lingshuang after realising her true motive, and the heroine becomes torn between loyalty to her homeland and love.