Three-year-old Sui An is abandoned in the wilderness and unexpectedly saves Su Jihan, the matriarch of a marquis's household, who adopts her as her daughter. After entering the estate, she hears a withered tree weeping and digs up a hidden wooden plaque. A few childish words even awaken her unconscious elder brother, Su Jinghan. At a palace banquet, she accidentally spills ink but instead helps the Grand Dowager Consort regain the ability to walk, earning the title of County Lady. At the grand assembly of ten thousand dynasties, an iron tree blossoms and Buddha's light offers protection, while the strange occurrences she casually points out help Duke Xiao avert a secret crisis. As the mystery surrounding the marquis's household and Sui An's origins gradually unfolds, she clutches a golden hairpin retrieved from the koi pond and points toward the depths of the imperial palace. With the innocence of a child, she brings unexpected turning points to everyone around her.